Déduire is a french third group verb. So, this verb is irregular and do not follow a regular conjugation pattern like first or second group verbs. Follow this link to see all the endings of the conjugation of most of the third group verbs :
conjugation rules and endings for the second group verbs.
Déduire is conjugated in interro-negative form. The interro-negative form being obtained by inversion of the subject, the placement of the negative adverb follow the same rules as in negative form, giving the following rules:
- in interro-negative form, the adverb
« ne » is always placed first if the subject is a pronoun.
- in simple tenses, the adverbs (
« ne ...pas »,
« ne...plus »,
« ne...jamais », etc...) surround the verb
déduire and the inverted subject pronoun.
- in compound tenses or in passive voice, the negative adverbs surround the auxiliary and the inverted subject pronoun.
For sound reasons, like in interrogative form, an euphonious
« t » is added to the pronoun of the third person:
« il »,
« elle »,
« on »,
« ils »,
« elles » except when the verb ends with
« t » or
« d »:
« ne déduira-t-il pas ? »,
« n'a-t-il pas déduit ? »,
« n'aura-t-il pas déduit ? ».
Finally, the interrogative form does not exist in subjunctive and imperative.
