Se duper is a french first group verb. So it follow the regular conjugation pattern of the first group like:
aimer.
Follow this link to see all the endings of the conjugation of the first group verbs :
conjugation rules and endings for the first group verbs.
Se duper is conjugated the same way that verbs that end in :
-er.
First group verbs always end with
-er as their infinitive. Endings of first group verbs are regular.
Note : Although endings are perfectly regular, spelling changes occur in the stems of verbs in
-cer,
-ger,
-yer,
-eter,
-eler,
-é-consonne(s)-er,
-e-consonne-er, verb
envoyer and similar verbs.
The verb
se duper is the reflexive form of verb
duper. In grammar, a reflexive verb is, loosely, a verb whose direct object is the same as its subject, for example, "I wash myself". More generally, a reflexive verb has the same semantic agent and patient (typically represented syntactically by the subject and the direct object) are the same. For example, the English verb to perjure is reflexive, since one can only perjure oneself. In a wider sense, the term refers to any verb form whose grammatical object is a reflexive pronoun, regardless of semantics; such verbs are also referred to as pronominal verbs, especially in grammars of the Romance languages. A reflexive verb is always conjugated with a reflexive pronoun. Here is the list of the french reflexive pronouns:
« me »,
« te »,
« se »,
« nous »,
« vous »,
« se ».
Se duper verb is conjugated in interrogative form. For sound reasons, 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 »:
« se dupe-t-il ? »,
« se dupa-t-il ? »,
« se dupera-t-il ? »,
« se sera-t-il dupé ? ».
Always in interrogative form, and always for sound reasons, an accent appears in first person present indicative tense when the verb ends with
« e ». An euphonious
« e » is replaced by
« é »:
« me dupé-je ? ».
Finally, the interrogative form does not exist in subjunctive and imperative.
