[ojbyrne]

I’m on shaky ground correcting French, but I think that should be “c’est lui.” Moi, toi, lui,…

[umanwizard]

You are correct. To expand a bit:

French pronouns have four possible cases: as the subject, direct object, or indirect object of a verb, or not an argument of a verb at all. The declensions are:

je/me/me/moi

nous (colloquial: “on”)/nous/nous/nous

tu/te/te/toi

vous/vous/vous/vous

il/le/lui/lui

elle/la/lui/elle

ils/les/leur/eux

elles/les/leur/elles

In this example, the pronoun is not the argument of a verb, so the fourth case is used (moi, lui, etc.)