Present Perfect: since vs for (B1)

About this exercise

This B1 set has 15 multiple-choice questions on two small words that cause many errors: since and for. Each sentence has a present perfect verb and a gap before a time expression. You decide whether the expression is a length of time or a starting point. Some options are tempting but wrong, such as from, ago, during and in, so you also practise telling them apart. Some questions end in a full clause, such as "we were five years old". Treat the clause as a starting point. After each answer, read the explanation and rewrite the sentence with the other word. Then check what the new version needs.

The rule in 30 seconds

Use for before an amount of time and since before the moment the situation began. Both words go with the present perfect in this quiz, where the situation is still true now. For also works with the past simple for a finished period.

have or has + past participle + for + length of time / since + starting point

forhow long, such as six months or ages

sincefrom when, such as March or last Christmas

since + clausean event that began the period, such as I started yoga

Learn from the errors

Common mistakes this set targets

Since with a length of time. He has owned that motorcycle since six months. → He has owned that motorcycle for six months.Six months is an amount of time, and an amount of time takes for.
For with a year. They have been married for 2015. → They have been married since 2015.A year names one point on the calendar, so use since.
Since + ago. I have lived here since five years ago. → I have lived here for five years.Ago is not used after since. For a length of time, use for.
When instead of since. I have felt much better when I started yoga. → I have felt much better since I started yoga.Since links a present state to the moment it began.
During for a length of time. My parents have lived abroad during over a decade. → My parents have lived abroad for over a decade.During names a period when something happens, not how long it lasts.

Frequently asked questions

How can I decide between since and for in one second?

Look at the words after the gap. If you can put a number before them, such as two weeks, use for. If they name a date or an event, use since.

Can I follow since with a full clause?

Yes. After since, the clause usually takes the past simple, as in "since the pandemic started". The main clause stays in the present perfect.

Is "for ages" correct?

Yes. Ages is informal for a long time, and it is a length of time, so it takes for.

Why does the question about a long friendship use for?

"A long time" is a length and not a date. The friendship is still true, so the present perfect and for fit together.