même: same, even, -self
Summary
Même has three distinct jobs — agreeing adjective meaning 'same', invariable adverb meaning 'even', and hyphenated intensifier meaning '-self' — and telling them apart is mostly about position and meaning.
Explanation
Même is a small word with three quite different jobs, and each one has its own agreement behavior. Recognizing which job même is doing in a sentence is mostly a matter of checking its position and what it means.
As an ADJECTIVE meaning 'same', même normally comes right after a determiner and before the noun, and it agrees in number (and, through the noun, effectively in gender too, since the article carries the gender): la même chose (the same thing), les mêmes livres (the same books). Here même behaves exactly like any other prenominal adjective.
As a reinforcing suffix meaning '-self', même attaches with a hyphen to a stressed (disjunctive) pronoun — moi, toi, lui, elle, nous, vous, eux, elles — and agrees in number with that pronoun: moi-même (myself), elle-même (herself), nous-mêmes (ourselves), eux-mêmes (themselves, masculine). Because the stressed pronoun already carries gender and number, même simply follows suit for the plural -s.
As an ADVERB meaning 'even', même is completely INVARIABLE, because adverbs never agree: même les enfants le savent (even the children know it), il n'a même pas répondu (he didn't even answer). In this use même typically comes before the word or phrase it emphasizes, and même si means 'even if'.
A quick test separates the three: if même can be replaced by 'even' / 'including' in English, it is the invariable adverb; if it can be replaced by 'the same' and sits between a determiner and a noun, it is the agreeing adjective; if it follows a stressed pronoun with a hyphen and reinforces '-self', it agrees with that pronoun.
Même also appears in a handful of fixed adverbial expressions that are worth learning as units: de même ('likewise, similarly'), quand même ('still, anyway', often expressing mild reproach or concession), and tout de même (an emphatic variant of quand même, roughly 'all the same'). All of these are invariable, like the adverbial même they are built on.
Examples
Nous avons acheté les mêmes livres. — We bought the same books. (même as an agreeing adjective meaning 'same', between the determiner les and the noun livres.)
Elle a fait le gâteau elle-même. — She made the cake herself. (même hyphenated to the stressed pronoun elle, agreeing in number (singular).)
Ils ont construit la maison eux-mêmes. — They built the house themselves. (eux-mêmes: même agrees in the plural with the stressed pronoun eux.)
Même les enfants le savent. — Even the children know it. (Invariable adverb même meaning 'even'.)
Il n'a même pas répondu à mon message. — He didn't even answer my message. (Invariable adverb même intensifying the negation.)
Même si tu es fatigué, il faut finir ce travail. — Even if you're tired, this work has to be finished. (même si = 'even if', invariable.)
Common mistakes
Mêmes les enfants ont les même droits.
Même les enfants ont les mêmes droits.
Même used as the adverb meaning 'even' is invariable: même les enfants ('even the children') never takes an -s, regardless of what follows. Writing mêmes here wrongly treats the adverb as if it agreed like an adjective. The second half makes the opposite mistake: when même means 'same' and functions as an adjective before a plural noun, it must agree: les mêmes droits ('the same rights'), not les même droits. The two uses need to be told apart — invariable for 'even', agreeing for 'same'.
Prerequisites
Related rules
memeagreementadverbs