动词
从一定意义上讲，英语语法就是动词的语法，因此，掌握动词的特性、变化、句型是学习英语语法的重中之重。为了能更好地理解下面的讲课内容，首先要搞清动词的几个基本概念。
1) be 动词和do动词：be动词也称状态动词，用于说明状态或性质，主要用于构成英语的主系表句型;do动词也称为行为动词，分及物动词和不及物动词;
2) 及物动词和不及物动词：不及物动词后面不跟宾语, 也没有被动语态; 及物动词后面一定要有宾语;
3) 双宾语结构和复合宾语结构：比较下面两个句子：
My mother made me a cake.
My father made me a doctor.
第一句是双宾语结构，即 My mother made a cake for me.
第二句是复合宾语结构，其句法功能为：My father made me be a doctor . 说明复合宾语结构中，宾语和宾语补足语之间有主谓关系.
4) 情态动词：must, should, ought to, can, may, need, used to 等动词称为情态动词，有三大特征：A. 不受主语人称和数的影响，如：He may go now. / May I go now? 句中may的形式不变;B. 否定时在后面加not, 如：You ought not to have cheated her. C. 与另一动词连用，中间不用 + to , 如上举例。
请根据上述原则，说出以下那种表达方式是对的：
A. She needs to see a doctor.
B. She doesnt need to see a doctor.
C. Does she need to see a doctor?
D. She needs not see a doctor.
E. She neednt see a doctor.
F. She doesnt need see a doctor.
G. She needs see a doctor.
从语法角度看，A、B、C、E是对的。
5) 助动词：帮助实意动词构成某种结构的词，如: He did come yesterday; I saw him in the office.