When do you use the word since

“Since” can be an expression of time, and it can mean “because”.

“Since” as a time expression

When used to express time, the word “since” means:
— from a time in the past until the present
— from a time in the past until another time in the past.

1. From a time in the past until the present

Because of its relationship with time “since” must be used with the correct verb tense. Have a look at these examples of a common mistake:

WRONG
He is out of the office since you last phoned.
As you may recall, the Paris office assists us with this project since it started.
Mr Jones is employed by the Company since September 2016.

In these three sentences the writers have made the mistake of using the Present Simple tense (is / assists / is employed) instead of the Present Perfect tense.

RIGHT
He has been out of the office since you last phoned.
As you may recall, the Paris office has assisted us with this project since it started.
Mr Jones has been employed by the Company since September 2016.

Note that these examples follow this pattern:
Present Perfect tense in the main clause and Past tense (or a date in the past) after “since”.

More examples:
No Public Authority or third party has raised any claims or allegations under Clause 4.1 since the Agreement was signed.

Since he joined the firm as a junior associate in 1998, he has become one of the most highly regarded lawyers in his field.

(Since joining… is an alternative structure that may be used in this type of sentence.)

In all sentences of this type you must use the Present Perfect tense in the main clause. However, the rule that you use the Past tense after “since” is flexible. Sometimes we can use the Present Perfect here as well. For example:

The department has been extremely busy since we have had an office in Mumbai.
I’ve been feeling much better since I’ve been taking more exercise.

We use the Past tense after “since” when we refer to a point in time in the past, and we use the Present Perfect after “since” when we refer to a period of time from the past until the present. We could rewrite the above two examples to refer to points in time (and use the Past tense after “since”) as follows:

The department has been extremely busy since we opened an office in Mumbai.
I’ve been feeling much better since I started taking more exercise.

2. From a time in the past until another time in the past

“Since” can also be used to express time from a starting point in the past until an end point in the past. Such sentences may follow this pattern:

Past Perfect tense in the main clause and Past tense after “since”.

We were sorry to lose MaxCo when they ceased operations in Poland in 2016. They had been a client of ours since they entered the country in 2003.

In 2013 I was asked to direct the company’s promotional film. I had not done anything like that since I worked in TV advertising in 1993.

When I arrived I realised that they had been in the meeting since 9 am.

It is also possible to use the pattern Past Perfect tense in the main clause and Past Perfect tense after “since”. For example:

It had been 20 years since I had directed any kind of film.

3. “Ever since”

You can add stress to “since” by adding “ever”.

Our two senior partners have known each other ever since they were at primary school.

He moved to London in 1994 and he has been living there ever since.

4. Do NOT use “since” to express present time, future time or general time

Note that in all the above examples, “since” is used to describe past time. When used to express time, “since” can ONLY be used in this way.

WRONG
Present
We want the office to start operating since now, or by the end of June at the latest.

Future
I’ll be in the bar since 7 o’clock this evening.

General time
The licence-granting procedure should not take longer than 90 days since the submission of the application.

Instead use “from”:

RIGHT
Present
We want the office to start operating from now, or by the end of June at the latest.

Future
I’ll be in the bar from 7 o’clock this evening.

General time
The licence-granting procedure should not take longer than 90 days from the submission of the application.

5. Do NOT use “since” to express duration

WRONG
The Landlord may terminate the Agreement with immediate effect if the Tenant is in arrears with payments since three months.

Although we would usually expect a decision within six weeks of making an application, the Claimant has now been waiting since ten weeks.

Instead use “for”:

RIGHT
The Landlord may terminate the Agreement with immediate effect if the Tenant is in arrears with payments for three months.

Although we would usually expect a decision within six weeks of making an application, the Claimant has now been waiting for ten weeks.

Another common mistake

WRONG
He worked at Microsoft since 2003 to 2006.

RIGHT
He worked at Microsoft from 2003 to 2006.

Do not use “since” with “to”. Use “from” and “to” or “from” and “until”. Another example:

He worked at the company from the moment he qualified until his retirement.

WRONG
According to the statement, no accidents at work or on the way to or from work have occurred since 2006 until now.

RIGHT
According to the statement, no accidents at work or on the way to or from work have occurred since 2006.

Because “since” — and the Present Perfect tense — incorporate “until now” into their meanings, including “until now” in the above sentence is not necessary.

“Since” meaning “because”

We do not recommend the course of action you propose since there is a risk that the employee will refer the matter to court.

This usage of “since” is rather formal, and may be ambiguous in some sentences because “since” is more commonly used to express time. Consider this example:

We have analysed the tax aspects of the transaction since we were instructed to do so.

This could mean “We have analysed the tax aspects because we were instructed to do so” or “We have been analysing the tax aspects from the time we were instructed to do so”.

As a result, I recommend using “because” or “as” instead of “since”.

Предлоги since и for имеют несколько значений. Основное — указание на период действия. Часто они появляются в похожих контекстах: например, в Past Perfect. Но заменять друг друга они не могут: нужно запомнить правила их использования.

Среди предлогов времени в английском эти два слова занимают особое положение: они обозначают не само время действия, а отсылают к периоду. И делают это по-разному. For отражает собственно период, а since его начальную точку. Кроме того, указание на время — не единственное значение for и since, они встречаются и в других контекстах. Чтобы разобраться с этими двумя словами, посмотрим на значения каждого из предлогов с примерами.

Предлог for

Первый из предлогов for and since обозначает период, на протяжении которого длилось событие и имеет значение «в течение определенного времени»:

When he came to the office, I had already worked for two hours — Когда он пришел в офис, я уже проработал два часа.

This apartment has been empty for years — Эта квартира пустует годами.

We go to the seaside for two weeks every year — Каждый год мы уезжаем на море на две недели.

My brother will be in Spain for the next week — Мой брат будет в Испании в течение следующей недели.

Из этих примеров видно, что предлог for может употребляться с разными временами: прошедшим, настоящим и будущим. Наиболее характерное время с for в качестве периода действия — форма Perfect, хотя его использование не обязательно. Например, период может относиться к будущему времени (He’s going to Brazil for the winter — Он уезжает в Бразилию на зиму).

При этом указание на период действия не мешает использованию других маркеров времени, например, повторяемости действия, как в примере We go to the seaside for two weeks every year («Каждый год мы уезжаем на море на две недели»).

Когда мы говорим о том, сколько времени длится действие к настоящему моменту, предлог for употребляется с временем Present Perfect. В таких примерах нужно внимательно отличать, since или for должно использоваться.

Mr Taylor has known me for three years — Мистер Тэйлор знает меня на протяжении трех лет.

В разговорном стиле предлог for может опускаться. Часто он опускается с вопросом how long (сколько, в течение какого времени) и не используется перед словом all:

We’ve lived in this house (for) six weeks — Мы живем в этом доме шесть недель.

How long have you been waiting (for)? — Сколько ты уже ждешь?

I’ve had a headache all day — У меня весь день болит голова.

Предлог since

Предлог since указывает на период события по-другому: он передает, когда началось действие, служит его отправной точкой:

We’ve been waiting since six o’clock — Мы ждем с шести часов.

We’ve known your brother since January — Мы знаем твоего брата с января.

Здесь может возникнуть вопрос, в каком времени используется since. Если for употребляется с различными глагольными формами, то since служит явным маркером времен Perfect:

I’ve been working since six o’clock and I’m getting tired — Я работаю с шести часов и начинаю уставать.

Типично употребление предлога since в отрицательных предложениях, чтобы подчеркнуть, когда в последний раз происходила ситуация:

We haven’t seen Jimmy since Christmas — Мы не видели Джимми с Рождества.

Предлог since может заменяться на предлог from с временами перфекта, когда необходимо подчеркнуть значение «начиная с этого времени»:

She’s been like that from (since) her childhood — Она такая с самого детства.

Хотя более типичное употребление from — с неперфектными временами. Предлог since в таких случаях использоваться не может.

This vase dates from the 17th century — Эта ваза датируется 17-м веком.

Правило since / for во временах Perfect

Итак, оба варианта предлогов используются с временами Perfect. Они оба указывают, сколько длится действие, но обозначают период по-разному. Предлог for служит для того, чтобы передать саму длительность, а since указывает только на начальную точку.

Сравните предложения:

I’ve known her for six months — Я знаком с ней шесть месяцев.

I’ve known her since last summer — Я знаком с ней с прошлого лета.

She’s been working here for a long time — Она работает здесь давно (длительное время).

She’s been working here since July — Она работает здесь с июля.

Правило since or for определяется не глаголом в предложении, а указанием на время, которое следует за предлогом. Если оно обозначает точку на шкале времени (last winter, July), то используется since. Если же за предлогом следует описание отрезка времени (six months, a long time), употребляется for.

Другие случаи употребления

Слово since в английском языке может выступать и в качестве предлога, и в качестве союза. То есть за ним может следовать не только существительное, обозначающее начало действия, но и придаточное предложение. Значение начала события при этом сохраняется: союз since переводится «с тех пор как».

I’ve known her since we were at college — Я знаю ее с тех пор, как мы учились в колледже.

You’ve drunk four cups of coffee since you came home — Ты выпил четыре чашки кофе, (с того момента) как пришел домой.

Хотя since может иметь и другие значения. Например, союз since может обозначать причину:

Since he had not paid the bill, the electricity was cut off — Поскольку он не оплатил счет, электричество отключили.

Когда мы говорим о союзах, появляется принципиальное различие между since и for: союз for не может обозначать период времени. Значение союза for — указание на причину:

There won’t be any delay, for all the differences are resolved — Задержек не возникнет, поскольку все разногласия устранены.

У слов for and since существуют и другие значения. Например, предлог for может обозначать цель и предназначение (to stop for a photo — остановиться, чтобы сделать фото) или причину (for many reasons — по многим причинам). Но основная сложность в употреблении for / since возникает с временем Perfect. Чтобы не путать их, нужно хорошо запомнить правило since or for.

В английском языке огромное количество времен. И каждый с лёгкостью способен запутаться в их разнообразии, поскольку очень сложно помнить о всех вариантах и тонкостях использования каждой из временных форм. Вот тут смогут помочь особенные слова – показатели времени. К этим словам можно отнести since.  Since – какое время в английском языке, узнаем из этой статьи.

Особенности английского союза «since»

Слово «Since» в английском языке встречается во многих функциях и может быть например предлогом, наречием либо союзом. Значение союза соединено с его речевым использованием; обсуждаемый союз воссоздает обстоятельственные связи подчинительного типа и в то же время будет неоднозначным: он может применяться в одном из своих двух смыслов – во временном либо в причинном. В виде временного союза он связывает кратковременные побочные предложения к основным, а в роли причинного союза объединяет придаточные основания и ключевые предложения в рамках сложноподчиненных систем.

Самая главная роль союза «since» во временном значении – образование временных связей привязанности. Этот союз включает в себя двойственный намек на время: он указывает на далёкое во времени начало определенного действия придаточного предложения, после какого выполняется действие основного предложения.

Причинные придаточные в рамках сложноподчиненных предложений могут показывать истинную либо косвенную причину определенного действия. В предложениях с «since» причинные отношения частенько приобретают определенные временные, целевые, условные и прочие оттенки.

Во временном значении у «since» только два значения: (1) после определенного эпизода в прошлом в наиболее поздний период времени и (2) регулярно (и до этого времени) после определенного эпизода.

Когда использовать since?

Как правило Since в основном используется, если нам нужно выделить, что действие случается с конкретного момента в прошлом по настоящее время. В основном мы пользуется времена группы Perfect с since.

Перевод since: на русский язык как правило переводится как: с; с тех пор как; с момента, когда

Present Perfect Simple

I have known Lena since we met at school. – Я знаю Лену с тех пор как мы познакомились в школе.

Since 2017, so much has changed in the project. – С 2017 года столько всего изменилось в проекте.

Present Perfect Continuous

He has been reading the newspaper since 9 am. – Он читает газету с 9 утра.

Правила использования since:

Во время использовании since поступка (или положение), совершающееся на протяжении какого-либо интервала времени, должно быть незавершенным во время написания предложения, а этап, когда этот поступок случился, должно быть известно.

Как правило такое время помечается конкретным месяцем, временем, днём, но не в коем случае неясным признаком (2-ая половина месяца, первые 3 дня недели). Из-за этого обычно в данной системе употребляются перфектные времена, преимущественно Perfect Continuous.

Конструкция:

• сущ + гл + предлог + начало действия (состояния).

Времена:

• Present Perfect + since + Past Simple

Например:

• I haven’t been here since April. – Я здесь не был с апреля.
• I have been waiting here since 2:00 pm. – Я жду тут с 14:00.
• I have been working on it since Christmas. – Я над этим работаю с Рождества.

Since и for во временах группы Perfect

Предлог since используется как значение «с» и показывает на первоначальный момент действия, какое раньше началось и длится до настоящего момента времени.

Where is Lera? – She’s in the room. She’s still asleep. She’s been sleeping since noon.	Где Лера? – Она в комнате. Она все еще спит. Она спит с полудня.
How’s your boyfriend? – I don’t know. I haven’t seen him since Christmas.	Как твой парень? – Не знаю. Я не виделась с ним с Рождества.
Victor is divorced. He’s been divorced since last year.	Виктор разведен. Он разведен с прошлого года.
Let’s go to some restaurant. I’m hungry. I haven’t eaten anything since yesterday.	Пойдем в какой-то ресторан. Я голодна. Я ничего не ела со вчерашнего дня.
Can I talk to the manager? – I’m sorry, she’s gone on business. – How long has she been gone?” – Since Tuesday.	Я могу поговорить с менеджером? – Простите, она уехала по делам. – Как долго её не было? – С вторника.
How’s your sister? – She’s fine. She’s been in France since Easter.	Как твоя сестра? – Она в порядке. Она во Франции с Пасхи.
You speak English better now. How long have you been teaching him? – Since March.	Ты уже лучше говоришь на английском. Давно его учишь? – С марта.

Since в качестве наречия

В виде наречия since используется как значение «с тех пор как, поскольку, так как».

We parted with Marina last year and I haven’t heard from him since.	Мы расстались с Мариной в прошлом году, и с тех пор я ничего о ней не слышал.
I spent a lot of money on clothes last month and I haven’t been shopping since.	В прошлом месяце я потратил много денег на одежду и с тех пор я не ходил по магазинам.
When I was 20, I tried some strong alcoholic beverages and got poisoned. I haven’t been trying any alcohol since.	Когда мне было 20 я пробовала некоторые крепкие алкогольные напитки и отравилась. С тех пор я не пью алкоголь.
Since you look tired, I’ll do the cleaning myself.	Так как ты выглядишь усталым, я сама сделаю уборку.
Since there are traffic jams on the roads, you need to leave an hour earlier.	Так как на дорогах пробки, вам нежно выехать на час раньше.

Since, Since then, Ever since в конце предложения

Так же некоторые предложения могут заканчиваться на since либо since then без более определенного указания времени. Так может быть, если оно понятно из контекста, слово since либо since then в даном случае – это наречие со значением «с тех пор». С каких именно пор – должно будет ясно из предложения.

• Marina and Rita had a big fight, they haven’t spoken since (since then). – Марина и Рита сильно поругались, они с тех пор не разговаривали.

Между since и since then в этом случае нет совсем разницы. Есть так же вариант ever since – буквально, «все время с того момента». Означает то же, что и наречия since, since then, но в «усиленном» варианте:

• Marina and Rita an argument. They haven’t spoken ever since. – Марина и Рита сильно поругались, они с тех пор никогда не разговаривали.

Разница между since и for

Данные два предлога очень похожи: они оба дают возможность уяснить, что поступок случался в течение конкретного времени.

Но for в таком варианте говорит, сколько конкретно времени действие уже происходит, а since – с какого времени.

При грамотной системе вы можете применять каждый из предлогов.

К примеру, сейчас октябрь, и вы хотите сообщить, что работаете в кафе уже три месяца. В таком случае вы можете сказать и “I have been working in this caf? since July” или “I have been working in this caf? for three months now”. Предлогу since важнее, когда вы начали работать, а for – сколько вы работаете (или работали).

По этой причине не следует употреблять since, если вы уволились неделю назад. В данном случае это уже будет ограниченное количество времени: с июля по октябрь – потому грамотнее будет поставить for.

Если вы хотите подчеркнуть, что начали работать в июле, используйте два предлога: after и for.

Например:

• I was working for three months after I got this job. – Я работал три месяца, пока не получил эту работу.

В той статье мы узнали какое время в английском языке since. И как они используются в грамматическом времени. Теперь, когда вы знаете, что из себя представляет since в английском языке, вы сможете большего достигнуть в изучении языка! Самое главное, все время совершенствовать свои знания!

There are several ways to use the word since and this can be confusing. So it’s time we spoke about the different meanings of since.

1) The First meaning of Since: Starting from a Time

You will probably know the meaning of since that means from a certain time in the past.

Here are some examples:

I’ve known Jasmin since she was a baby.

Robbie has been studying English since 2014.

Lidia and Bjorn have been dating since January.

Ms Holden hasn’t gone done to the cellar since she saw a mouse there.

Farrell hasn’t read a book since the age of 18.

Because this meaning of since expresses that something started in the past and is still valid today, you will find since often used with the present perfect tense. For more information about this tense, follow the link.

Hwoever have a look at this sentence again:

I’ve known Jasmin since she was a baby.

You don’t need to use the present perfect twice in a sentence. Once is enough. If you’ve used the present perfect in the first part of the sentence, the part of the sentence that follows beginning with since will be in the past simple tense.

Can you see this?

I’ve known Jasmin = in present perfect

Since she was a baby = in past simple.

Since Verb + ing

To make things easier and avoid having to deal with tenses, I have a simple idea for you. Use a verb with –ing.

Here are some examples:

He saves tons of money since switching to a cute little car.

She’s famous since appearing on national television.

Didn’t you say you were feeling much better since eating only vegetarian food?

2) The second meaning of since: Because

Since can also mean for the reason that, so the meaning is the same as because.

It is more formal than because.

Here are some examples:

Since you were the one who dropped the key in the sewer, you need to pay for a new key.

The two parties broke off the negotiations, since there was no progress.

Do you want to stop for a little something to eat, since you said you were hungry?

She is called Lizzie? Hm, that can’t be her real name, since the last time I met her she introduced herself as Margaret.

Confused by Since

Can it sometimes be confusing to use since, since it can have two meanings?

Good question. Yes, it can.

Let’s consider this sentence:

Maret laughed since her cousin told her a joke.

Is Maret laughing because her cousin told her a joke, or from the time her cousin told the joke?

Well, of Maret was laughing from the time her cousin told the joke, that means Maret is still laughing now. That doesn’t make sense, although it would be possible. So I need to understand that since means for the reason that.

It would make the sentence even more confusing when I fiddle with the tenses in this sentence.

Suppose I say: Maret was laughing since her cousin told her a joke.

Now I can understand that she was laughing for a longer time, so from the time that her cousin told the joke. But it’s still not very likely. The since in this sentence means because.

What about this one?

Maret has been laughing since her cousin told her a joke.

Note that the tenses are now the same as in the standard sentence for since meaning from the time that. I’ve used present perfect. So now I really do mean since as from the time that her cousin told her a joke. The meaning is odd, but there we are.

Want to hear another one that could be quite ambiguous (= open to different meanings)?

Here you go:

I missed you since you were gone.

Since could both mean from the time this person left, or because the person left.

Idioms with Since

There are also some expressions with since that you might like to know. All these expressions use since in the meaning of from the time that.

Since Forever

Sometimes people say: since forever.

This is slang and means for as long as I can remember or forever.

For instance you ask how long Sue and Tom have been married. – Oh, since forever, must be almost 60 years now.

I like your watch. Is it new? – No, I’ve had this watch since forever. You just didn’t notice it.

Since Then / Since That Time

Suppose you’ve just told your friend about something that happened at a certain time and you want to tell what happened after that. You don’t need to say the time again, but you can just say since then or since that time.

Here are some examples:

I had lunch with Adrian at Food Place last month and haven’t seen him since then.

(You don’t need to say again that it was last month when you saw Adrian for the last time.)

Sofia delivered two healthy twins three years ago; she hasn’t gone back to work since that time.

Ever Since / Many Times Since

With ever since you can do the same as with since then: refer to a certain time again and say when it was the last time that something happened. When you say ever since, you’re implying it was for a long time.

They met at the barbecue and have been together ever since. (And they’re going to be together for the rest of their lives, or that’s how it looks.)

We met in high school and have been friends ever since.

I’ve bought handmade soap at Soaps for Us when I was looking for a present and I’ve been back there many times since.

Many times since also means for a long time, but with breaks.

The Difference Between Since Then and Ever Since

When do you use since then and when ever since?

Since then is used for negative sentences and positive sentences and can be used for situations that are still true today or for a period in the past.

Ever since is used for things that you are still doing or that are still continuing.

So you can’t say: I haven’t seen him ever since, because seeing someone is not a long action that you can keep doing.

But it is okay to say: They have been together since then.

Since on Its Own

Is it okay to use since on its own, at the end of the sentence?

Let’s have a look at an example and then we’ll decide whether this is possible or not:

I had lunch with Adrian at Food Place last month and haven’t seen him since.

What do you think? Okay or not okay?

Em. I had to look this one up in a grammar book (I checked more than one grammar book). I still don’t know the answer, as no one talks about this problem. I know that people say since at the end of the sentence, so that seems to be accepted English. But I wanted to know what grammarians think about it.

As soon as I find out, I will let you know.

Now you can do a quiz.

Quiz

You can do this quiz online here.

Decide in which meaning since is used in the following sentences.

1 That toast can’t be ready yet, since you haven’t plugged in the toaster.

2 The Transport Minister has had a stomach operation, and he’s been on a diet since then.

3 Since we still have a long journey home, we’d better start going on our way now.

4 They’ve had to give away their cat and haven’t been allergic ever since.

5 I don’t need to cook when Donnie and Tina come here, since they took me to a restaurant when I stayed at their place.

6 The children have been hooked to piano lessons since they first started taking them in the autumn of 2012.

7 What’s the score since that disastrous opening set?

8 Since I was in town anyway, I thought I would pay you a visit.

9 The first restaurants established themselves in the block around 2000, and since then the whole area has been developing into an entertainment district.

10 Since global warming is measured per country, and not per capita, China and India seem to be the worst polluters in the world.

More about since here.

Giving Good Reasons – As, Because, Since, Seeing As, Seeing That

When starting a sentence with the word «since», add a comma after the first clause (group of words containing a subject and a verb).

When starting a sentence with the word «since«, add a comma after the first clause (group of words containing a subject and a verb).

Since Mary is a doctor, she can prescribe drugs.

Since Mary is a doctor she can prescribe drugs.

We do not generally need a comma before «since» in mid-sentence.

I should skip dessert since I’m trying to lose weight.

I’ve been studying German since 2020.

Contents

• 1. How to Use Since in a Sentence
• 2. Commas in the Middle of a sentence
• 3. Starting a Sentence with ‘Since’
• 4. References

1. How to Use ‘Since’ in a Sentence

«Since» can be:

• A preposition to refer to a time in the past. Prepositions are followed by a noun or a pronoun (e.g., «I’ve been married since 2015.»)
• A subordinating conjunction to explain the reason for something (e.g., «My brother can achieve it since he has experience.»), or to indicate a period from a time in the past («I’ve been doing this since I arrived here.») Note that subordinating conjunctions, unlike prepositions, are followed by a subject and a verb.
• An adverb to mean «ago» or between then and now (e.g., «She went to the mall this morning, and I haven’t seen her since.»)

2. Commas in the Middle of a sentence

In the middle of a sentence, we do not commonly use a comma in front of «since«.

I’d like to travel to Japan since its culture is truly unique.

It’s been raining since yesterday.

Albert has lived in Rome since 2015.

Isabella has been looking for a job since she left school.

I wonder where my niece is. I haven’t seen her since Tuesday.

There are particular situations, however, where commas may be required. For example, use commas to set apart non-essential information.⁽¹⁾

Alice is planning to return to Madrid, maybe next month, since she has developed an emotional attachment to the Spanish culture.

I love her, despite our relationship stumbles, since she has been respectful and patient.

The Spanish government debt, already high since the financial crisis, exploded during the 2020 debacle.

3. Starting a Sentence with ‘Since’

As mentioned before, we can use «since» to introduce a group of words containing a subject and a verb (clause).

Since my sister is an excellent cook, she prepared a delicious meal.

In this situation, if the clause introduced by «since» comes at the beginning of a sentence, we must add a comma after the first clause.

Since I want to learn a new language, I registered for a Chinese course.

Since I want to learn a new language I registered for a Chinese course.

More examples:

Since they’re going to arrive next week, we have plenty of time to prepare for the meeting.

Since copper is still the material of choice for electric power, the demand of copper is growing by leaps and bounds.

Since the current situation seems a perfect setup for yield curve control, the European Central Bank will probably implement this policy next year.

Instead of introducing a clause, you can use «since» to introduce a noun phrase. Phrases, unlike clauses, do not contain a subject and a verb.

Since 1980 the US GDP has been declining.

The comma after short introductory phrases like these can be easily omitted if the sentence is clear.⁽²⁾

Since then I have been learning marketing.

Since 2018 Rebecca has been working here.

4. References

(1) Strunk JR., William; White, E.B. The Elements of Style. Chapter 1 — Elementary Rules of Usage.

(2) Kaufman, Lester; Straus, Jane. The Blue Book of Grammar and Punctuation. Chapter 2 (punctuation).