How do I know if a verb in the perfect tense should be conjugated with avoir or être?

The perfect tense is used when we would like to describe an action that we have already done. It is usually formed by using the present tense of the verb avoir followed by a past participle. For example, " I played " in French would be " J'ai joué " However, there are some verbs which are conjugated with the verb être instead of avoir. The best way to remember which verbs use être is by remembering the mnemonic Dr. Mrs. Vandertramp. http://howardfrenchpages.weebly.com/uploads/1/8/5/8/1858927/9718669.jpeg?321