Grandfather is forgetful and often repeats himself when he tells a story.

祖父很健忘,他讲故事时常重复。

She ought not to be forgetful of her duties.

她不该玩忽职守。

I'm a bit forgetful these days.

这些日子我有点健忘。

Every actor ought to know his lines backwards before he goes on stage,as nervousness may make him forgetful.

所有演员在上台前都应当把台词记得滚瓜烂熟,因为一紧张就容易忘词。