Since vs for
Use 'since' with a starting point in time (a date, year, event, or time of day) to say when a situation began: 'since 2019', 'since Monday'. Use 'for' with a length or duration of time (a number of minutes, days, or years) to say how long it has lasted: 'for three years', 'for a while'. Both commonly pair with the present perfect.
The rule
Since vs for at a glance
Since
For
- Core meaning
- A starting point in time
- A length/duration of time
- Typical follow-on
- a date, year, day, event, time of day
- a number + unit of time (minutes, days, years)
- Example
- since 2015, since Monday, since I moved here
- for two years, for a week, for a long time
- Common tense pairing
- present perfect / present perfect continuous
- present perfect / present perfect continuous, but also past simple
- Answers the question
- When did it start?
- How long has it lasted?
- Can it start a clause?
- Yes, 'since I arrived' (since + clause)
- No, 'for' takes a noun phrase, not a clause
Which one do I need?
Since or for?
Every answer at a glance
since
Since names the point when something began and links it to now, so it goes with the present perfect: have lived here since 2019.
Our team has used this software since last January.
for (with the past simple)
Since links a starting point to now, so it does not fit a finished period. Say how long it lasted with for and the past simple.
He taught in Hanoi for three years before he returned to Lima.
for
For goes with a length of time: how long something lasts. It works with any tense: have studied for, studied for, will stay for.
I have been learning Korean for about eighteen months.
since
Only since can introduce a clause with its own subject and verb. Use the past simple after since and the present perfect in the main clause.
Since I joined the gym, I have felt much more energetic.
How to use since vs for
What is the difference between 'since' and 'for'?
'Since' and 'for' both commonly appear with the present perfect to talk about situations that started in the past and continue now, but they answer two different questions. 'Since' answers 'when did it start?' with a fixed point in time. 'For' answers 'how long has it lasted?' with a length of time.
A simple test: if the phrase names a moment on a calendar or clock (a date, a day, a year, an event), use 'since'. If it names a quantity of time (a number of minutes, days, months, years), use 'for'.
- I've worked at this company since 2017.a starting point on the calendar
- I've worked at this company for seven years.a length of time
- I've worked at this company since seven years.'seven years' is a duration, not a starting point → for seven years
'Since' with an event or a whole clause
Beyond dates, 'since' can be followed by an event ('since the wedding') or an entire clause with its own subject and past-tense verb ('since I moved to Manchester'). This structure (since + past simple clause, main clause + present perfect) is common in natural speech and writing.
'For' cannot introduce a clause in the same way; it only takes a noun phrase describing a quantity of time.
- Since I started this job, I've learned three new software programs.since + past simple clause
- Since the merger, the company has doubled in size.since + event
- For I started this job, I've learned three new programs.'for' cannot introduce a clause → since I started
Can 'for' be used with the past simple?
Yes. Unlike 'since', 'for' works with any tense that involves duration, including the past simple for a finished period. 'Since' almost never appears with a past simple main clause, because it implies a link to the present that the past simple does not carry.
- We lived in Nairobi for four years before moving back home.finished duration → for + past simple
- We lived in Nairobi since 2010.a finished period doesn't fit 'since' → We have lived there since 2010
- They will be travelling for six weeks this summer.'for' with a future duration
Common mistakes with since vs for
Find what is wrong in each one, then open it to check.
1I have lived here since five years.What's wrong? Show the fix
I have lived here for five years.
'Five years' is a duration, not a starting point, so it must follow 'for', not 'since'.
2She has worked here for 2018.What's wrong? Show the fix
She has worked here since 2018.
'2018' is a fixed point on the calendar, so it needs 'since', not 'for'.
3I haven't seen him for last month.What's wrong? Show the fix
I haven't seen him since last month.
'Last month' marks a starting point in time, so 'since' is required rather than 'for'.
4For I moved to this city, I've made many new friends.What's wrong? Show the fix
Since I moved to this city, I've made many new friends.
Only 'since' can introduce a clause with its own subject and verb; 'for' takes a noun phrase, not a clause.
5We have been married since ten years.What's wrong? Show the fix
We have been married for ten years.
'Ten years' is a length of time, which pairs with 'for'; 'since' would need a starting point like '2014'.
6I am waiting for the bus since twenty minutes.What's wrong? Show the fix
I have been waiting for the bus for twenty minutes.
A duration reaching the present needs the present perfect continuous, and 'twenty minutes' is a length of time, so it takes 'for', not 'since'.
Practise
Write your own
Write a sentence that uses since or for, about you, your studies or your town.
Since vs for in IELTS
Speaking
- Part 1 questions about how long you've done something (a hobby, a job, living somewhere) are the perfect test of since/for control: 'I've been learning the guitar for about a year, since my cousin gave me his old one.' Using both accurately in one answer is a strong Band 6+ signal.
- Avoid the common slip of saying 'since three years'; pause and self-correct to 'for three years' if you catch it; examiners credit accurate self-correction.
Writing
- In Task 1, use 'since' to anchor the start of a trend to a labelled year: 'Since 2010, internet usage has more than doubled.' Use 'for' when describing how long a trend has continued: 'The figure has remained stable for almost a decade.'
- In Task 2, 'since' works well to introduce the historical starting point of an ongoing issue: 'Since the introduction of smartphones, attention spans have reportedly declined.'