按使用目的,句子可分为陈述句、疑问句、祈使句和感叹句。一、陈述句(Declarative Sentences)说明一个事实或陈述一种看法,包括肯定句和否定句。肯定句变否定句注意两点:1.如果有助动词(has,have,had,will)/be/情态动词的话,直接在其后加not。2.如果句子中没有助动词(has,have,had,will)/be/情态动词的时候,由助动 According to the purpose of use, sentences can be divided into statements, interrogative sentences, imperative sentences and exclamatory sentences. First, the statement (Declarative Sentences) A ​​statement of fact or statement, including positive and negative sentences. Positive sentence negative sentence Note two points: 1. If the verb (has, have, had, will) / be / modal verb, followed by not. 2. If there is no auxiliary verb in the sentence (has, have, had, will) / be / modal verb,