（三）句子的种类句子是一个独立的语言单位，表示一个完整的思想。按使用目的可分为陈述句、感叹句、疑问句和祈使句；从结构上又可分为简单句、并列句和复合句。按使用目的分：一、 陈述句That boy always helps others.Tom was not at home yesterday.He is too late to catch the bus.二、 疑问句（一般疑问句、特殊疑问句、选择疑问句和反意疑问句）Are you a doctor?How often do you have an English party?Which would you like better, tea or coffee?She is too young to go to school, is she?三、 感叹句（一） What +a /an+形容词+可数名词的单数形式+主语+谓语！=（二）How+形容词+a/an +可数名词的单数形式+主语+谓语！What a beautiful girl she is! = How beauti
