She has a propensity to exaggerate.

她爱言过其实。

He tends to exaggerate the difficulties.

他往往夸大困难。

It isn't that he lied exactly, but he did tend to exaggerate.

他不见得是真的说谎，但他的确是有意夸大。

People tend to exaggerate small changes.

人们倾向于夸大小的变化。

It's difficult to exaggerate the importance of sleep.

睡眠的重要性再怎么说也不为过。