French_Connaître - to know, be familiar with

Connaître is an irregular verb. Irregular verbs are so named because they do not follow any of the regular conjugation patterns. But that doesn't mean that every irregular French verb is unique; many of them share a conjugation pattern with at least one other verb. By learning how to conjugate one verb in a group and memorizing the list of similar verbs, you'll be able to conjugate all the verbs in that group. French has five irregular -RE verb patterns.

Website Reference: http://french.about.com/od/verb_conjugations/a/connaitre.htm?nl=1