1 作主语时谓语动词要用第三人称单数，如：Something is wrong with his bike.2 形容词修饰它时要放在它的后面，如：I have something important to tell you.3 一般用于肯定句中。

但也可用于征求意见并希望得到肯定回答的疑问句中，如：There is something wrong with it.Would you like something to eat?。