do和does以及have的用法

1.作为行为动词,跟其他动词一样,如study,play等.他的意思是“做”等.如：

We usually do our homework in the afternoon.

He does his homework in the evening.

2.作为助动词,也就是帮助主要动词构成否定和疑问等.

We don't like bananas.

Do you like apples?

Does he like English?

He doesn't like swimming.

上面有一句He does his homework in the evening.要是变成否定句就成了这个样子：

He doesn't do his homework in the evening.

这里加上了助动词doesn't,而原来的主动词does变成原形do了.

①have可以作为助动词,本身无词义,主要用于构成各种时态、语态、语气以及否定和疑问结构.（那此时的have还是has就要看具体的人称而定）

②have也能作为实义词,解释为“有”,用于疑问句和否定句时要用助动词do.

问题He doesnt have any coffee.

就是第二种：他没有咖啡.为否定句,用助动词do的第三人称单数形式does.在这样的助动词后面一定要用动词原形have.