For and since are two common time expressions in English that are used to describe duration and starting points in time.
For or Since
| FOR | SINCE |
|---|---|
| A period of time | A starting point in time |
| for 10 minutes | since 8 o’clock |
| for 5 days | since Monday |
| for many years | since 2015 |
| for a long time | since I was a child |
Common Time Expressions
Common Expressions with For
- for 5 minutes
- for two weeks
- for several months
- for 10 years
- for a while
- for a long time
Common Expressions with Since
- since yesterday
- since last night
- since Monday
- since March
- since 1995
- since the beginning of the meeting
Sentence Structure
For and since are most commonly used with the Present Perfect and Present Perfect Continuous tenses.
- I have lived here for ten years.
- I have lived here since 2016.
- She has been working here for a long time.
- She has been working here since last summer.
Common Pitfalls
The most common mistake is using since with a period of time.
- Incorrect: I’ve been here since two hours.
- Correct: I’ve been here for two hours.
Tips:
- If you can ask “How long?”, use for.
- If you can ask “From when?”, use since.
Last Updated on January 20, 2026
You messed up. You forgot to include “ago” in a since statement. “since three years ago”