Prevent，阻止、阻礙、阻撓。prevent doing sth，阻止做某事。prevent sb from doing sth，阻止某人做某事。prevent通常會接所有格形容詞+動名詞或接受詞+from+動名詞。當主詞沒有必要列出時，prevent可以直接接動名詞，也可以接名詞。

prevent例句

You can't prevent my leaving.

You can't prevent me from leaving.

I want to prevent his getting sick.

I want to prevent him from getting sick.

This campaign is designed to prevent drowning.

Preventing stealing is our main goal this year.

We are working to prevent forest fires.

This vaccine will prevent malaria.

prevent sth/sb from doing sth

from可用可不用。使用from，則句型為主謂賓+介詞短語作狀語（現代語法稱這個介詞短語為動詞的補足語）。

不用from，則句型為主謂賓結構，動名詞復合結構作賓語。動名詞的邏輯主語為代詞時，正式語體用所有格表示，非正式語體用賓格表示。