实义动词指的是有具体的动作含义的词，他是一个大类，其中包含着很多的分支，因此知晓了实义动词的用法和语法的规则，英语的语法和一些比较常见的或者英语阅读中的句子的含义都是容易就能理解的。至于情态动词，这是一类助动词，也是动词的一个分支，不过作为助动词在一些语法上的使用规则大家要明晰。下面就相关的语法的知识给大家做详细的解释，供大家参考学习。

　　实义动词和情态动词是根据动词的句法功能分类的。情态动词又叫情态助动词。

　　一、实义动词也叫主动词，有具体的词汇意义，表示主语发出的动作或所处的状态。在陈述句中，实义动词可以单独作谓语。实义动词加表语(主补)、宾语或状语构成谓语部分。

　　She is an English teacher and she works hard. (单词动词作谓语)

　　He enjoys swimming and gave us a performance last Sunday. (单词动词作谓语)

　　Mr Smith has been teaching in a middle school for 30 years. (加助动词作谓语)

　　二、助动词不能单独做谓语，后面要加主动词，用来帮助主动词的某种形式构成疑问句、否定句、进行时态、完成时态、被动语态和虚拟语气等语法变体。

　　助动词分为基本助动词和情态助动词两类。

　　(一)基本助动词没有词汇意义(be: is, am, are; was, were; have / has / had been; being, having been; do: do, does, did; have: have, has, had...)。

　　(二)情态助动词具有不同的情态意义。(will会，将, would会，将; shall将, should应该; can可能，也许, could可能; may也许, might可能; muts需要，, have / had to不得不; used to过去常常, need需要, dare敢, ought to应该;...)

　　如：Did he give you a performance last Sunday? (加did构成疑问句)

　　No, he didn't give us a performance last Sunday. (加didn't构成否定句)

　　I haven't received his letter for a whole month. (加haven't构成完成时态)

　　Something must be done to make the rivers clean.

　　(加must be构成含情态意义的被动语态)

　　If everyone bought one soft-drink can each day and threw it away, there would soon be a huge mountain of rubbish. (加would构成虚拟语气)