Usage note : since

As a preposition

In time expressions

since is used in English after a verb in the present perfect or progressive present perfect tense to indicate when something that is still going on started. To express this French uses a verb in the present tense + depuis :

I’ve been waiting since Saturday

= j’attends depuis samedi

I’ve lived in Rome since 1988

= j’habite à Rome depuis 1988

When since is used after a verb in the past perfect tense, French uses the imperfect + depuis :

I had been waiting since nine o’clock

= j’attendais depuis neuf heures

In negative time expressions

Again since is translated by depuis, but in negative sentences the verb tenses used in French are the same as those used in English :

I haven’t seen him since Saturday

= je ne l’ai pas vu depuis samedi

I hadn’t seen him since 1978

= je ne l’avais pas vu depuis 1978

As a conjunction

In time expressions

When since is used as a conjunction, it is translated by depuis que and the tenses used in French parallel exactly those used with the preposition depuis (see above) :

since she’s been living in Oxford

= depuis qu’elle habite à Oxford

since he’d been in Paris

= depuis qu’il était à Paris

Note that in time expressions with since French native speakers will generally prefer to use a noun where possible when English uses a verb :

I haven’t seen him since he left

= je ne l’ai pas vu depuis son départ

she’s been living in Nice since she got married

= elle habite à Nice depuis son mariage

For particular usages see the entry since.

Meaning because

When since is used to mean because, it is translated by comme or étant donné que :

since she was ill, she couldn’t go

= comme elle était malade or étant donné qu’elle était malade, elle ne pouvait pas y aller

As an adverb

When since is used as an adverb it is translated by depuis :

he hasn’t been seen since

= on ne l’a pas vu depuis

For particular usages see C in the entry since.

Big English-French dictionary. 2003.