The one thing the two words have in common is their function; which is, they act as auxiliary verbs. Otherwise also known as helping verbs, auxiliary verbs add functionality to main verbs.

Common verb forms used in French are auxiliary verbs, expressions with avoir and être and modal verbs. The perfect tense with avoir and être The perfect tense is used to talk about something ...

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.