To form the perfect tense you need a subject, an auxiliary verb and a past participle. Perfect tense with 'être' in French The perfect tense is used to say what you did or have done in the past.

In your scientific paper, use verb tenses (past, present, and future ... such as an infinitive (to do) or a participle (doing), its subject is implied to be the subject of the clause, or sometimes ...

The present participle is a word formed from a verb. The English translation of the present participle ends in -ing. It can be used as a verb or as an adjective.