Since vs For
Side-by-side comparison of Since (with a starting point) and For (with a duration).
Use 'since' with a specific point in time when something started ('since 2019', 'since Monday'). Use 'for' with a length of time ('for three years', 'for two hours'). Both typically pair with the present perfect to describe situations that began in the past and continue now.
Since vs For: At a Glance
| Question | Since (with a starting point) | For (with a duration) |
|---|---|---|
| What follows the word | A point in time: a date, a clock time, a day, an event, or a clause: 'since 2015', 'since Monday', 'since I was a child'. | A length or duration: 'for three years', 'for two hours', 'for a long time', 'for ages'. |
| What it answers | When did this start? Names the moment the situation began. | How long has this been true? Names the total length of time. |
| Typical tense | Most often present perfect or present perfect continuous: 'I've worked here since 2019.' | Most often present perfect or present perfect continuous: 'I've worked here for five years.' Also possible with past simple to mean a finished duration. |
| Can it introduce a clause? | Yes: 'since I moved to Berlin', 'since she was a teenager'. The clause is usually past simple. | No — 'for' is followed by a noun phrase indicating duration, not a clause. |
| Other meanings to watch for | 'Since' can also mean 'because' as a conjunction: 'Since you're here, let's start'. That use is unrelated to time. | 'For' has many other uses (purpose, recipient, exchange). The duration use is just one of them. |
Examples Side by Side
Since (with a starting point)
I have lived in Berlin since 2018.
For (with a duration)
I have lived in Berlin for six years.
Same situation. 'Since 2018' names when it started; 'for six years' names how long it has lasted. Both pair naturally with present perfect.
Since (with a starting point)
She has been studying since this morning.
For (with a duration)
She has been studying for three hours.
Both work with the present perfect continuous to emphasise an ongoing activity. Choose 'since' with a start point, 'for' with a length.
Since (with a starting point)
We haven't seen each other since the wedding.
For (with a duration)
We haven't seen each other for ages.
'The wedding' is a point in time → since. 'Ages' (= a long, vague duration) → for.
Since (with a starting point)
He has worked here since I joined the company.
For (with a duration)
He has worked here for as long as I can remember.
'Since' can introduce a clause anchoring the start point. 'For' is followed by a duration phrase, not a clause.
Frequently Asked Questions: Since vs For
What is the difference between 'since' and 'for'?
'Since' marks the starting point of a situation: 'since 2019', 'since Monday', 'since I was a child'. 'For' marks the length of time: 'for three years', 'for two hours'. Both typically appear with the present perfect to describe something that began in the past and is still true now.
Why do 'since' and 'for' usually go with present perfect?
Because they describe a span that begins in the past and continues to the present moment — exactly what present perfect (and present perfect continuous) is designed to express. 'I have lived here since 2019' or 'I have lived here for five years' both link the past to now. With finished past actions, prefer past simple instead.
Can I use 'for' with the past simple?
Yes, when the duration is finished: 'I lived in Tokyo for three years' (I no longer live there). With present perfect, 'I have lived in Tokyo for three years' implies I still live there. The same 'for' phrase works with both tenses, but the meaning shifts.
Is 'since' ever followed by a clause?
Yes — 'since' is unusual among time expressions because it can take either a noun phrase or a clause. Noun phrase: 'since 2019'. Clause: 'since I moved to Berlin'. The clause after 'since' is usually past simple, while the main clause is present perfect.
Does 'since' always mean 'from a starting point'?
No. 'Since' has a second meaning as a conjunction expressing reason or cause, similar to 'because': 'Since you're here, let's start'. This use is unrelated to time. Context normally makes the meaning obvious.
Why is 'I have lived here since five years' wrong?
Because 'five years' is a duration, not a starting point. After 'since' you need a moment in time. Either say 'since 2019' (a point) or 'for five years' (a length). The mismatch is one of the most common ESL errors with present perfect.