赖世雄教你学英语语法
两句的连接方法
2-5:连词的独立用法
and,or,but通常置于两个并列的主句之间，以发挥连词的功能
有时我们也可见到and,or,but变成大写，置于单一的主句（即简单句）句首，形成独立的用法。惟此类用法必须要有上下文才能存在。
例如：无上下文：and he took my advice.(x)
有上下文：he was not sure as to how to handle the problem,but i told him not to worry about it until his father came.and he took my advice.(o)
（他不能确定如何处理这个问题，但是我告诉他在他父亲来以前别担心。而他接受了我的劝告。）
无上下文：but he left just the same.(x)
有一下文：since it was raining quite hard,i asked him to stay lest he should catch a cold walking in the rain.but he left just the same.(o)
（因为雨下得很大，我要他留下来以免走在雨中着凉，但他还是走了。）