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(huì)接所有格形容詞+動(dòng)名詞或接受詞+from+動(dòng)名詞。當(dāng)主詞沒(méi)有必要列出時(shí)，prevent可以直接接動(dòng)名詞，也可以接名詞。

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.

from可用可不用。使用from，則句型為主謂賓+介詞短語(yǔ)作狀語(yǔ)（現(xiàn)代語(yǔ)法稱(chēng)這個(gè)介詞短語(yǔ)為動(dòng)詞的補(bǔ)足語(yǔ)）。

不用from，則句型為主謂賓結(jié)構(gòu)，動(dòng)名詞復(fù)合結(jié)構(gòu)作賓語(yǔ)。動(dòng)名詞的邏輯主語(yǔ)為代詞時(shí)，正式語(yǔ)體用所有格表示，非正式語(yǔ)體用賓格表示。