How to use 'since' and 'for'

This is something that many English learners - even advanced learners - find challenging. For example, I often hear people say things like:

"I live in Brussels since 20 years".

There are two things that are not quite right here. Let’s start with the use of the word ‘since’.

Since  is used to refer to when the action started. For example:

I have lived in Southend since the year 2000.

I haven’t eaten ice cream since last summer.

She has been sick since 4 January.

They haven’t stopped talking since 9am this morning.

He has been scared of spiders since he was a child.

In contrast, for  is used to talk about the specific length of time (22 years, eight months, two weeks….) For example:

I have lived in Southend for 22 years.

I haven’t eaten ice cream for eight months.

She has been sick for two weeks.

They haven’t stopped  talking for three hours.

He has been scared of spiders for 33 years.

You may have also noticed that the present perfect tense is used in all of the above sentences and not the present tense.

So to go back to the first sentence above:  *I live in Brussels since 20 years*. The correct version would be:

I have lived in Brussels for 20 years  = Present perfect tense [..........]  +  for + specific length of time.

But if you want to talk about when it started:

I have lived in Brussels since 2003   =  Present perfect tense [..........]  +  since + when the action started.

So, to summarise:

For is used to talk about the specific length of time (5 years, 2 weeks, 7 days, 3 hours….).

Since is used to refer to when the action started (the year 2000, last summer, 9am...).

Use the present perfect when talking about something that started in the past and is still true in the present.

In case you’re wondering, you can use other tenses with ‘since’ and ‘for’ such as the past perfect and the present perfect continuous. If you feel ready and you’d like more information on these other tenses (and a bit about how to use them with 'since' and 'for') I suggest the following excellent explanations from Perfect English Grammar:

Using the Past Perfect Tense (perfect-english-grammar.com)

Present Perfect Simple or Present Perfect Continuous Tense? (perfect-english-grammar.com)

I hope this helps to explain how to use ‘since’ and ‘for’. If you have any questions or comments, please do not hesitate to contact me or leave a comment.