La forme simple de l’impératif
The present imperative is used to give an order or to offer advice.
In the imperative mood, the subject pronoun is not used.
In the imperative, verbs are only conjugated in three grammatical persons (tu, nous, and vous), and most of the conjugations are the same as the present tense.
-ER VERBS
They conjugate in the same way as the present indicative, except the tu form loses the final –s (the nous and vous forms remain unchanged). For example:
parler
(tu) parle
(nous) parlons
(vous) parlez
aller
(tu) va
(nous) allons
(vous) allez
Verbs that are conjugated like -ER verbs (meaning that in the indicative the tu form ends in -es), such as ouvrir and souffrir, follow the same rules as -ER verbs. For example:
ouvrir
(tu) ouvre
(nous) ouvrons
(vous) ouvrez
(EXCEPTION: the tu form keeps the -s ending if the verb precedes the pronoun y or en. For example: donnes-en or vas-y.)
-IR and -RE VERBS
The imperative conjugation of all regular (and most irregular) -IR and -RE verbs are the same as the present indicative. For example:
finir
(tu) finis
(nous) finissons
(vous) finissez
faire
(tu) fais
(nous) faisons
(vous) faites
However, there are four exceptions:
avoir
(tu) aie
(nous) ayons
(vous) ayez
être
(tu) sois
(nous) soyons
(vous) soyez
savoir
(tu) sache
(nous) sachons
(vous) sachez
vouloir
(tu) veuille
(nous) veuillons
(vous) veuillez
Negative Imperatives
The word order is the same as that of all other simple verb conjugations:
Finis! - Finish!
Ne finis pas! - Don't finish!
Ne le finis pas! - Don't finish it!
Affirmative Imperatives
The word order for affirmative commands is different from other tenses and moods: all pronouns follow the verb and are connected to it and to each other with hyphens:
Finis-le! - Finish it!
Allons-y! - Let's go!
Mangez-les! - Eat them!
Donne-lui-en! - Give him some!