leave的过去式是leaved还是left?

问题描述:

leave的过去式是leaved还是left?
书的内容要求:
Present and Past Tense Verbs
A verb changes to show when an action happens.
Use a present tense verb to tell what happens.now.
leave The hardest part was when someone _____ to go war.
即:The hardest part was when someone leaved to go war.
(最难的部分是当一个人离开去战争)

left是leave的过去式啊亲~