1、I unremembered where I put my keys yesterday.
我忘记了昨天放钥匙的地方。

2、She tried hard to unremember the painful memories from her past.
她努力试图将过去的痛苦回忆都忘记。

3、The trauma was so intense that he could not simply unremember it.
那个创伤太强烈，他无法简单地忘记它。