Do you confuse the words since and for? Some languages only have one word that means both, so it's common for learners to mix them up!
Since and for are prepositions that combine with other words to tell us something about the verb. They also both refer to the past, but in different ways.
Here's everything you need to know to use since and for in English!
In this post:
When to use since
When to use for
Tips for deciding between since and for
When to use since
Since refers to “since when?” and is followed by some amount of time, including dates, days, and times of day. (Since can also be a conjunction, but here we're focusing on how to use it as a preposition.)
Since is used when referring to a specific time in the past that you can pinpoint, and it implies that the action started back then and continues until now.
| Example | What else we know | Why since |
|---|---|---|
| I’ve lived here since 2019. | The speaker still lives here now. | 2019 is a specific year or date, and the action of living there continues until now. |
| I’ve been in Pittsburgh since Tuesday. | The speaker is still in Pittsburgh. | “Tuesday” is a specific day, and the action of being in Pittsburgh continues until now. |
| I’ve lived in England since I was a child. | The speaker still lives in England. | Even a long period of time (like childhood) can be considered specific, and here, the speaker continues living in England. |
| I’ve been waiting here since 3 o’clock. | The speaker is still waiting. | Three o’clock is a specific time, and the action of waiting continues until now. |
Verb form used with since
Did you notice anything else in common with these examples? It’s the verb! Since is used exclusively with the present perfect tense—and not the simple past tense:
| Verb tense: present perfect | Action completed? | Since |
|---|---|---|
| I’ve worked here since January. | ❌ (I still work here.) |
✅ |
| We haven’t spoken since last year. | ❌ (We’re still not speaking.) |
✅ |
| It's been snowing since Friday. | ❌ (It's still snowing.) |
✅ |
| Verb tense: simple past | Action completed? | Since |
|---|---|---|
| I worked here last January. | ✅ (I no longer work here.) |
❌ |
| We didn't speak last year. | ✅ (We’re speaking again.) |
❌ |
| It snowed on Friday. | ✅ (It stopped snowing after Friday.) |
❌ |
When to use for
For refers to “for how long?”, and is used for durations of time rather than specific points in time. Unlike since, the preposition for is used with numbers and more general lengths of time.
1. Use for with numbers
Whenever the length of time is a number, use for.
- I've lived here for 5 years.
- I waited for 3 days before my package finally came.
- I've been waiting for the doctor for 90 minutes.
2. Use for for general lengths of time
When the time we’re referring to is vague or unspecific (we can’t pinpoint exactly when it started) we use for.
- I've been waiting here for a while.
- I've lived there for a few years.
- I've been a member here for decades.
As you can see, what follows for is different than what follows since!
Verb form used with for
Unlike since, for can be used with both the simple past tense and the present perfect tenses. That's because for can imply that the action continues until now (just like since)—but it doesn’t have to!
| Verb tense: present perfect | Action completed? | For |
|---|---|---|
| I’ve been on vacation for 2 days. | ❌ (I'm still on vacation.) |
✅ |
| I've lived here for 5 years. | ❌ (I still live here.) |
✅ |
| Verb tense: simple past | Action completed? | For |
|---|---|---|
| I was on vacation for 2 days. | ✅ (Now I'm back from vacation.) |
✅ |
| I was there for 5 years. | ✅ (I later moved away.) |
✅ |
Tips for deciding between since and for
Here are things to ask yourself when deciding between since and for:
- What’s my verb tense?
- Am I talking about a specific point in time (since), or a duration of time (for)?
- Am I talking about a number of something (for), or a date (since)?
- Am I talking about when (since), or how long (for)?
Improve your English, one preposition at a time
If you’ve struggled with these two words for a while now, there’s no need to worry! You’ve been learning languages since the day you were born, and we’re here to keep cheering you on 💪