Prevent，阻止、阻碍、阻挠。prevent doing sth，阻止做某事。prevent sb from doing sth，阻止某人做某事。prevent通常会接所有格形容词+动名词或接受词+from+动名词。当主词没有必要列出时，prevent可以直接接动名词，也可以接名词。

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，则句型为主谓宾+介词短语作状语（现代语法称这个介词短语为动词的补足语）。

不用from，则句型为主谓宾结构，动名词复合结构作宾语。动名词的逻辑主语为代词时，正式语体用所有格表示，非正式语体用宾格表示。