For and since both talk about time that started in the past and continues to now, and both live in the same tense — the present perfect. The difference is what follows them: for measures how long (a duration: for ten minutes, for six months, for a long time), while since marks when it started (a starting point: since 9 a.m., since March, since we met).
The 25 sentences below go from warm-up to challenge and include the classic traps: for with a clause, since in negative sentences, all day without either word, and the tense choice that pairs with each. Every answer is checked on the spot with a one-line explanation, so each miss teaches the rule instead of just the answer.
For vs Since Quiz: 25 Questions
Questions come in rounds of 10, from all 25 on this page. Finish a round to continue; every question and answer is also listed below.
Warm-up · duration or starting point
I have lived in this city ___ 2019.
All questions, answers and explanationsOpen to check your work after the quiz.
1. I have lived in this city ___ 2019.
- for
- since
- during
- from
Correct answer: since · 2019 is a starting point — a moment the situation began — so it takes since. For would need a duration: for six years.
2. She has been a nurse ___ twelve years.
- since
- for
- ago
- by
Correct answer: for · Twelve years is a duration — how long, not when it started — so it takes for. Since would need a point: since 2014.
3. We have waited ___ half an hour.
- since
- from
- for
- during
Correct answer: for · Half an hour measures length of time, so it takes for. Rule of thumb: if you can count it, it is a duration.
4. He has worked here ___ he graduated.
- for
- since
- during
- while
Correct answer: since · He graduated is a clause marking the starting moment, and since is the only one of the pair that can introduce a clause: since he graduated.
5. They have been married ___ ten years.
- since
- for
- from
- at
Correct answer: for · Ten years is a duration, so it takes for. Compare: they have been married since 2016 — same meaning, different measuring.
6. I haven't seen her ___ the conference in April.
- for
- since
- during
- by
Correct answer: since · The conference in April is a starting point, so it takes since — negative sentences follow exactly the same rule as positive ones.
7. It has been raining ___ three hours.
- since
- for
- from
- over
Correct answer: for · Three hours is a duration: for three hours. If you named the start instead — since noon — you would use since.
8. She has loved jazz ___ she was a child.
- for
- since
- when
- during
Correct answer: since · She was a child is a clause marking when it began, so it takes since. For can never be followed by a subject + verb clause in this sense.
9. I have known my best friend ___ we were six.
- for
- since
- from
- that time
Correct answer: since · Since takes the clause we were six. Test: can you put a calendar date in its place? Since 2004 works, so since + clause works.
10. He has been at the company ___ a long time.
- since
- for
- during
- over
Correct answer: for · A long time is a duration even though it is vague, so it takes for. Since never pairs with vague lengths — only with points.
11. ___ Monday, the system has crashed four times.
- For
- Since
- During
- While
Correct answer: Since · Monday names the starting point, and sentence-initial Since + present perfect counts events from that point to now.
12. We haven't had a proper holiday ___ four years.
- since
- for
- in
- from
Correct answer: for · Four years is a duration: for four years. (American English also allows in four years with negatives, but for is the safe, universal choice.)
13. She has had this car ___ 2021.
- for
- since
- from
- by
Correct answer: since · 2021 is a point in time, so it takes since. For 2021 would be wrong — for must be followed by a length, not a date.
14. I've had a headache ___ this morning.
- for
- since
- from
- during
Correct answer: since · This morning is treated as the starting point when the morning is past: since this morning. Compare for the whole morning, which is a duration.
15. They have been studying ___ two hours without a break.
- since
- for
- during
- ago
Correct answer: for · Two hours is a duration: for two hours. During would need an event (during the lecture), not a length of time.
16. Nothing has changed here ___ I left.
- for
- since
- when
- while
Correct answer: since · Since introduces the clause I left — the moment that starts the unchanged period. For cannot introduce a clause like this.
17. My parents have run the shop ___ almost thirty years.
- since
- for
- during
- over
Correct answer: for · Almost thirty years is still a duration — modifiers like almost, nearly, and just over do not turn it into a point: for almost thirty years.
18. Which sentence is correct?
- I live here since 2020.
- I have lived here since 2020.
- I am living here since 2020.
- I lived here since 2020.
Correct answer: I have lived here since 2020. · Since + a situation continuing to now requires the present perfect: I have lived here since 2020. Present simple with since is the classic error — especially for speakers of languages that use the present tense here.
19. Which sentence is correct?
- She works here for five years.
- She is working here for five years.
- She has worked here for five years.
- She work here for five years.
Correct answer: She has worked here for five years. · A duration continuing to the present needs the present perfect: has worked for five years. Works for five years describes a habit or schedule, not elapsed time.
20. We've been renovating the office ___ June.
- for
- since
- from
- at
Correct answer: since · June is a starting point: since June. Present perfect continuous works with both for and since — the choice still depends on point vs duration.
21. He's been waiting ___ over an hour.
- since
- for
- during
- by
Correct answer: for · Over an hour is a duration (over = more than): for over an hour. Since would need the clock time: since 3 p.m.
22. I've been awake ___ 5 a.m.
- for
- since
- from
- at
Correct answer: since · 5 a.m. is a precise starting point: since 5 a.m. From 5 a.m. describes a schedule (the store opens from 5 a.m.), not elapsed time up to now.
23. Which sentence uses NO preposition before the time expression?
- I have waited for two days.
- I have waited since Tuesday.
- I stayed home all day.
- I have waited for nine hours.
Correct answer: I stayed home all day. · All day, all week, all year take no preposition: I stayed home all day. For two days, since Tuesday, and for nine hours all require one.
24. ___ we last spoke, the team has doubled in size.
- For
- Since
- During
- From
Correct answer: Since · Since we last spoke is a clause marking the starting point. Note the tense split: since + past simple clause, then present perfect in the main clause.
25. How long ___ you ___ Spanish?
- do / study
- have / been studying
- are / studying
- did / studied
Correct answer: have / been studying · How long with an activity continuing to now takes the present perfect (continuous): How long have you been studying Spanish? The answer then uses for or since.
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Duration or Starting Point?
Every for/since question reduces to a single test: does the phrase after the gap measure how long (a duration) or mark when it began (a starting point)? Durations take for — for ten minutes, for three weeks, for years, for a long time. Starting points take since — since 8 o'clock, since May, since 2015, since the meeting, since we moved.
- for + duration: for two hours, for six months, for decades, for a while.
- since + starting point: since Monday, since last summer, since the accident.
- since + clause: since I was a child, since we last spoke — for can never do this.
- all day / all week / all my life: no preposition at all.
Calendar test: if you could replace the phrase with a date (2019, March 3rd, 9 a.m.), use since. If you could replace it with a number of units (3 years, 20 minutes), use for.
Why For and Since Live With the Present Perfect
For and since connect the past to the present, which is exactly the job of the present perfect: I have lived here since 2020 (and still do). If the situation is finished, English switches to past simple and drops since entirely: I lived there for five years (but not anymore), or I lived there from 2015 to 2020.
The error that follows learners longest is not the preposition but the tense: present simple instead of present perfect. I live here since 2020, she works here for five years, and we are married since June all sound wrong to native ears, because the present simple describes the present only; it cannot reach back to a starting point.
- Continues to now → present perfect: has been, have lived, have known + for/since.
- Finished period → past simple + for: I worked there for two years. (Not since with the past simple: since needs a period that runs up to a later reference point.)
- Period up to a moment in the past → past perfect + for/since: By 2020 I had lived there for ten years. I hadn't seen him since 2010.
- Finished period with both ends named → from … to/until …: from June to September.
- Emphasize ongoing activity → present perfect continuous: have been waiting for an hour.
Five Mistakes That Give You Away
Beyond the tense error, for and since attract a short list of recurring mistakes. Most come from direct translation: many languages use one word for both ideas (Spanish desde, French depuis, Japanese 〜から, Arabic منذ), so the duration/point split has to be learned fresh.
- I am knowing him since 2015 → I have known him since 2015 (stative verbs rarely go continuous, but they still need the perfect).
- Since three hours → for three hours (since never takes a duration).
- For 2022 → since 2022 (for never takes a date or year).
- I live here for ten years → I have lived here for ten years (present simple cannot span time up to now).
- During two years → for two years (during needs an event or period noun: during the summer, during the meeting).
If your first language has a single word covering both (desde, depuis, منذ, 〜から), treat every English sentence as a forced choice: point or duration? Then check the verb: it should be have/has + participle, not the present simple.
Since as a Conjunction — and the Meaning Shift
Since does double duty in English: besides marking a starting point, it can mean because (since you're here, let's start). The time sense pairs with the present perfect in the main clause; the because sense pairs with any tense and usually opens the sentence.
For has its own double duty too — as a conjunction meaning because (formal/literary: for it was already late). In modern writing that use is rare, so in everyday texts a for before a time phrase almost always means duration.
- Time since: Nothing has changed since we met. (present perfect main clause)
- Because since: Since we have time, let's review the report. (any tense)
- It's been years since I flew — with it's been / it has been, the since-clause uses past simple.
- For as conjunction = because, formal: We stayed inside, for the storm had worsened.
How to Practice For and Since Until It's Automatic
After the quiz, write five true sentences about your own life: how long you have studied English, lived in your city, known your best friend, worked at your job, owned your phone. Write each one twice, once with for and once with since (for six years / since 2020). Doing both versions makes you convert durations into starting points, which is the decision the quiz tests.
Then check your own writing. Paste those sentences (or any email) into PromGee's free grammar checker: it flags the wrong preposition and the wrong tense together and explains the rule.
Keep practicing
Frequently Asked Questions
What is the difference between for and since?
For is used with a duration — a length of time such as for three years or for ten minutes. Since is used with a starting point — a moment the situation began, such as since 2020, since Monday, or since I was a child. Both are normally used with the present perfect.
Do you say 'since three years' or 'for three years'?
For three years. Three years is a duration, so it takes for. Since would need the year the period started: since 2023. The quick test: dates and clock times take since; numbers of units take for.
Why do we use the present perfect with for and since?
Because for and since connect a past starting situation to the present moment, which is exactly what the present perfect expresses: I have lived here since 2020 means I still live here. If the period is finished, English switches to the past simple with for alone: I lived there for two years.
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