Learn French: Je donne des leçons de piano depuis un mois. - I have been giving piano lessons for a month.

In French, when an action started in the past and is still happening right now, you use the present tense along with depuis. Because you are still giving lessons today, French just says Je donne (I give). English uses "have been giving", which makes this a very common trap for learners!

I thought depuis meant "since". Why does it mean "for" in this sentence?

Depuis actually means both "since" and "for"! It translates to "for" when it is followed by a duration or length of time, like un mois (a month) or deux ans (two years). It translates to "since" when it is followed by a specific starting point in time, like depuis janvier (since January).

Why is it leçons de piano instead of leçons du piano?

When a noun is used to describe another noun to tell us what kind of thing it is, French connects them with just de instead of a combined article like du (de + le). Think of de piano as acting like an adjective here to mean "piano-related".

Could I use pendant instead of depuis to say "for a month"?