He worked hard all his life. (划线部分在句中作状语，修饰动词worked)

　　He is a school student in No. 1 Middle School. (划线部分在句中作定语，修饰名词student)

　　Having finished his homework, the boy went on to help his mother. (划线部分在句中作状语，修饰整个句子)

　　并列句就是由并列连词所连接起来的两个简单句。常用的并列连词有：and, or, but, so, while, when等。and用作并列连词，连接两个并列句时，可表示并列关系、递进关系、因果关系。or可以表示并列关系，也可表示因果关系，but表示转折关系，so可表示因果关系。while可表示比较或对比，when 则表示时间，相当于and at that time(就在那时)。如：

　　Work hard, and you will succeed. (and表示因果关系)

　　Hurry up, or you will be late for the film. (or表示因果关系)

　　He is old, but he still works as hard as young people. (but表示转折关系)

　　Mr. Li is generous and outgoing, so we all gets on well with him. (so表示因果关系)

　　I earn only 50 dollars a week, while she earns 80 dollars. 我一个星期只赚50美元，而她却赚80美元。(while表示比较、对比) (from www.nmet168.com)

　　I was going to leave home when the telephone rang. (when表示时间，相当于and at that time)

　　复合句就是含有两个或两个以上主谓结构的句子。这种结构中，必定有一个主谓结构是句子的主句部分，而另一个主谓结构则是句子的次要部分，即从句部分。常见的从句有：定语从句、名词性从句、状语从句等。从句部分一般都有引导词引导这个从句。如：

　　As is known to all, China is getting more and more powerful. (As 引导一个定语从句)

　　What he says doesn’t suit what he does. (本句包含两个名词性从句：What he says 是一个主语从句；what he does 是一个宾语从句)

　　Where there is a will, there is a way. (Where引导一个表地点的状语从句)