Organizing a neighborhood block party often involves pointing out who made a mess—or making sure you get credit for the food! To emphasize who performed an action in French, we use the structure C'est + stressed pronoun + qui.
Verb Agreement with "Qui"
The most important rule for this structure is that the verb following qui must match the pronoun that comes right before it. Even though qui acts as the subject, the verb conjugates as if the stressed pronoun were the actual subject.
First and Second Person
When using moi (me), toi (you), nous (us), or vous (you all), the verb directly mirrors what it would be for je, tu, nous, or vous.
| I am the one who claims the credit for the barbecue. | C'est moi qui revendique le mérite du barbecue. |
| You are the one who created all this mess! | C'est toi qui as créé toute cette pagaille ! |
Notice in the second example how the past tense auxiliary verb is as (the tu form of avoir), not the third-person a.
This rule works exactly the same way for plural pronouns, where you will use the standard -ons or -ez endings:
| It is we who are contributing to the neighborhood party. | C'est nous qui contribuons à la fête du quartier. |
| Are you the ones who claim the credit for the skewers? | C'est vous qui revendiquez le mérite des brochettes ? |
Third Person Singular
For the third-person singular, use the stressed pronouns lui (him) or elle (her). The verb takes the standard il/elle conjugation.
| He is the one who boasts about having bought the cups. | C'est lui qui se vante d'avoir acheté les gobelets. |
Third Person Plural (Ce sont)
When emphasizing "them" (eux for masculine/mixed groups, elles for feminine groups), there is a slight shift. Instead of C'est, grammatically strict French uses the plural Ce sont.
The verb after qui is then conjugated in the third-person plural (ils/elles form).
| They are the ones who contribute to reducing the mess. | Ce sont eux qui contribuent à réduire la pagaille. |