Stressed / disjunctive pronouns (moi / toi / lui)
Summary
Stressed (disjunctive) pronouns (moi, toi, lui, elle, nous, vous, eux, elles) appear after prepositions, for emphasis, in c'est sentences and when a pronoun stands alone.
Explanation
The stressed (or disjunctive) pronouns are moi, toi, lui, elle, nous, vous, eux, elles. They are the forms French uses whenever a pronoun is not functioning as the immediate subject or object glued to a verb: when it needs to "stand on its own feet".
Their main jobs are: after a preposition (avec moi, chez eux, pour elle, sans toi); alone in short answers (Qui veut du café ?. Moi !); for emphasis alongside the subject, often doubling it (Moi, je préfère le thé; Lui, il ne sait pas); after c'est and ce sont (C'est moi, Ce sont eux); and in compound subjects (Toi et moi, nous partons).
Several forms differ from the subject pronouns, and that is where mistakes happen. The third person is lui / elle in the singular and eux / elles in the plural: never il / ils after a preposition. So you say avec lui (not avec il) and pour eux (not pour ils); je/tu have no stressed use and become moi/toi.
They also build a few fixed patterns: with -même for "-self" (moi-même = myself, eux-mêmes = themselves), with aussi and non plus (Moi aussi ; Moi non plus), and in comparisons after que (plus grand que moi). In all of these the verb-attached forms would be ungrammatical.
A common pitfall for English and Spanish speakers is using the subject form after a preposition (avec je, pour il) by analogy with the subject pronoun. Another is dropping the doubling that French prefers for emphasis: to stress "I", you usually say Moi, je…, not just an emphasised je.
Rule of thumb: if the pronoun follows a preposition, stands alone, comes after c'est, or is being emphasised, switch to the stressed set moi / toi / lui / elle / nous / vous / eux / elles.
Examples
Tu viens avec moi ou avec eux ?Are you coming with me or with them?After prepositions: moi, eux (not je, ils).
Qui a fait ça ?. Moi ! Et lui aussi.Who did that?. Me! And him too.Stressed forms stand alone and after aussi.
Moi, je préfère le thé ; lui, il aime le café.I prefer tea; he likes coffee.Doubling for emphasis: moi/lui next to the subject pronoun.
C'est nous qui avons gagné.It's we who won.After c'est, the stressed form is required.
Elle l'a fait elle-même.She did it herself.-même attaches to the stressed pronoun.
Common mistakes
C'est je qui ai raison.
C'est moi qui ai raison.
After c'est, French requires a stressed (tonic) pronoun (moi, toi, lui, elle, nous, vous, eux, elles) not a subject pronoun like je. Say c'est moi qui ai raison, not c'est je qui ai raison.
Prerequisites
Related rules
pronounsdisjunctiveemphasis