We use since and for when we talk about time — especially when we talk about how long something has been happening. But they are not the same.
The difference is actually very easy:
- Use since to talk about the starting point of the action.
- Use for to talk about the length of the time.
Let’s look at each one.
1. Use SINCE for the Starting Point
Since shows when something started. You use it with a specific point in time.
That could be:
- a day
- a date
- a time
- or a moment in the past
Examples:
- I’ve lived here since 2020.
- She’s been working since Monday.
- We’ve known each other since high school.
- It’s been raining since 3 p.m.
- He’s been sick since yesterday.
You’re telling the moment when something began.
2. Use FOR to Talk About the Duration
For shows how long something has been happening. You use it with a period of time (not a date or day).
That could be:
- hours
- days
- months
- years
Examples:
- I’ve lived here for three years.
- She’s been working for five days.
- We’ve known each other for a long time.
- It’s been raining for two hours.
- He’s been sick for a week.
You’re talking about the amount of time something has lasted.
Compare Since and For
Let’s look at the same idea with both words:
- I’ve had this car since 2019.
- I’ve had this car for five years.
Another one:
- They’ve been friends since college.
- They’ve been friends for ten years.
Quick Trick to Remember
- Since = from when it started
- For = for how long it lasted
You can also think:
- Use since + a point in time
- Use for + a period of time
Final Thoughts
If you’re talking about the beginning of something → use since.
If you’re talking about the length of time → use for.
Here’s a full sentence using both:
I’ve been learning English since 2021, and I’ve studied it for two years.