肯定句中谓语如果是行为动词即实意动词时,变为疑问和否定句时只能加助动词do。如:I like English. 变为否定句时不能说:I not like English. 而是 I don't like English.
这个要讲清楚不太好说,举个例子就明白啦,很简单的:肯定句:He plays football .否定句:He doesn't play football .疑问句:Does he play football ?
没有意思的,