but /bʌt, bət/ I. conj. 然而，但是：He would like to go, but he can’t! 他想去，可没法去。not only…but also不但…，而且…: He is not only our teacher but also (he is) our close friend.他不光是我们的老师，也是我们的好朋友。［注］ not only…but also 连接两并列主语时，谓语与临近的主语一致：Not only he but also his parents are kind to us.不仅他，而且他父母对我们都很好。（见not条） not…but…不是…，而是…［考句］Not that John doesn’t want to help you, but that it’s beyond his power.不是约翰不想帮你，而是他无法帮你。II. prep.1.除…之外(用在no, all, nobody, who, where等后面): There’s no one here but me. 这里没别人，只有我。Who but George would do such a thing?除了乔治有谁会做这种事? last but one (two)倒数第二(三)：His house is the last but one in this street. 他的房子在这条街是倒数第二座。but that 若不是(后跟从句，主句中的谓语动词常用虚拟语气形式)： He would have helped us but that he was short of money at that time. 要不是当时他没钱，他本来会帮助我们的。but for若不是(后跟名词，句子的谓语动词常用虚拟语气形式)［考句］ But for the flood, the ship would have reached its destination on time要不是洪水的话，船本来会准时抵达目的地。［考句］He might have been killed but for the arrival of the police.要不是警察及时赶到他可能已经被杀害了。can/could do nothing but do sth.只好：She could do nothing but lie down and weep.她别无他法，只好躺下哭泣。have no choice but to do sth. 只好干某事：［考句］That was so serious a matter that I had no choice but to call in the police.那件事如此严重，除了请警察我别无选择。but then (again)但再一寻思：I agree she types accurately, but then again, she’s very slow.我同意说她打字错的很少，但再一想速度太慢了。［注］只有当前面出现do 时，不定式就不用to，如：I have nothing to do but wait for you. ‖III.adv. 仅仅：He is but a child. 他只是个孩子。He left but an hour ago.他只是一小时前才离去。