My sister have a headache.修改病句

My sister have a headache.修改病句
My sister have a headache.修改病句

My sister have a headache.修改病句
have 改成has
因为主语是my sister,所有动词要用第三人称单数.
懂了么?

my sister had a headache

改为My sister has a headache.
My sister是第三人称单数，谓语动词要用单三形式

My sister has a headache.

My sister has a headache.

have改为has
句子主语My sister是第三人称，所以谓语动词必须用单数形式。