并列连词
but:但是,可是,而
He is old, but he looks very young.
他老了,但他看起来很年轻。
Li Li likes violin but doesn't like piano.
李莉喜欢小提琴,(但是)不喜欢钢琴。
(but 后面省略了主语Li Li,因为与前面的主语成分相同)
Mary likes violin, but Tom doesn't.
玛丽喜欢小提琴,而汤姆不喜欢。
(doesn't后面省略了like violin,因为与前面的成分相同)
He isn't a teacher but a doctor.
他不是(一个)老师,而是医生。
They came here not for money but for the life.
他们到这儿来,不是要钱,而是要命。
注意
but所连接的句子,句中如果某些成分与前面相同,则可以省略。