mistake是可数还是不可数

mistake是可数名词。当mistake是名词时，其含义为错误，失误，口误，其复数形式为mistakes。例如：I found a mistake in that sentence.我发现那个句子有一个错误。

mistake表示错误

1、She made a mistake over the bill. 她把账算错了。

2、You made a mistake about the time. 你弄错了时间。

3、Don’t make any mistake about me. 不要误解我的意思。

by mistake 错误地

1、I’m sorry,I opened one of your letters by mistake.

对不起，我错拆了你的一封信。

2、The nurse gave me the wrong medicine by mistake.

护士给我吃错了药。