The Académie française keeps a standalone entry just for the word "depuis," a sign of how often it gets confused with its two neighbors, pendant and il y a. All three can land on the English word "for" or "ago" in a dictionary, which is exactly why English speakers reach for the wrong one so often. The fix has nothing to do with vocabulary. It is about which verb tense each word expects to sit next to.
Once that link between the time word and the tense clicks, the choice stops being a guess and becomes a small grammar reflex, the kind that eventually runs on autopilot in conversation.
Which word do you need for something that is still happening?
Depuis pairs with the present tense to describe a state or action that started in the past and is still true now. This is the one that trips up English speakers hardest, because English uses a perfect tense ("I have worked here for three years") while French stays in the present.
- J'habite à Paris depuis 2019. (I have lived in Paris since 2019.)
- Elle travaille ici depuis six mois. (She has worked here for six months.)
- Nous attendons depuis une heure. (We have been waiting for an hour.)
Notice depuis works with both a specific date ("depuis 2019") and a duration ("depuis six mois"). Either way, the situation is still ongoing at the moment you speak. If the action has actually stopped, depuis with the present tense is the wrong choice.
Which word do you need for a duration that is finished, or just described as a block of time?
Pendant describes a stretch of time as a whole, without committing to whether it continues into the present. It usually appears with the passé composé (a finished action) but can appear with other tenses too, because its job is to describe the length of the period, not its relationship to now.
- J'ai vécu à Lyon pendant cinq ans. (I lived in Lyon for five years.) The stay is over.
- Il a plu pendant toute la nuit. (It rained all night.) The rain has stopped.
- Pendant les vacances, je lis beaucoup. (During the holidays, I read a lot.) A recurring block of time, not a single finished event.
The test: can you replace "pendant" with "during the whole of" or "for the length of" without changing the meaning? If yes, pendant is doing its job correctly.
Which word do you need for "ago"?
Il y a marks a specific point counted backward from the present moment, and it is the direct match for English "ago." It never describes an ongoing situation and never pairs with the present tense. It almost always shows up with the passé composé, since it is anchoring a completed event.
- J'ai déménagé il y a trois ans. (I moved three years ago.)
- Elle est partie il y a dix minutes. (She left ten minutes ago.)
- Il y a longtemps, ce village était un port de pêche. (A long time ago, this village was a fishing port.)
A useful shortcut: if the English sentence ends in "ago," you need il y a. If it starts with "for" or "since" and describes something still true, you need depuis.
Comparing the three at a glance
| Word | Tense it expects | What it signals | English match |
|---|---|---|---|
| depuis | present (for ongoing states) | action started in the past, still true now | for / since |
| pendant | passé composé, or any tense describing a block | a duration, finished or recurring, as a whole | for / during |
| il y a | passé composé | a point in time counted back from now | ago |
The three words rarely compete for the same sentence, because each one answers a slightly different question: is it still happening (depuis), how long did it last as a block (pendant), or when exactly did it happen relative to now (il y a). Learning the tense each word travels with removes almost all of the guesswork that a straight vocabulary list creates.
Where the confusion usually creeps back in
Even learners who know the rule slip when a sentence mixes past and present in the same breath, or when they translate word for word from English instead of asking which of the three questions above the sentence is really answering. Reading the tense first, before reaching for depuis, pendant or il y a, solves most of these slips.
This is a rule that looks simple on a page and still causes hesitation in live conversation, because you have to choose while speaking, not while reviewing a worksheet. Practising it out loud, in real exchanges rather than fill-in-the-blank drills, is what makes the choice automatic. Yann Darmon, a certified French teacher, builds lessons around exactly this kind of recurring trouble spot. A free trial lesson at frenchwithyann.com is a straightforward way to see whether depuis, pendant and il y a finally stop feeling interchangeable.
Common questions
Why does depuis sometimes use the present tense for something that started in the past?
Because depuis describes a situation that is still true right now. French treats it as one continuous present state, not a completed past event, so it keeps the present tense even when English switches to a perfect tense like "have lived."
Can pendant and depuis ever describe the same period?
The period can be the same length, but the framing differs. "J'ai vécu à Lyon pendant cinq ans" closes the period, you no longer live there. "J'habite à Lyon depuis cinq ans" leaves it open, you still live there.
Is il y a only used for exact numbers of years?
No. It works with any unit of time and any specific point in the past: "il y a dix minutes" (ten minutes ago), "il y a longtemps" (a long time ago), "il y a un mois" (a month ago). What matters is that it marks a moment counted back from now, not a duration.