- 1.
但是；可是；而(是) -
• He is rich，but not happy. 他虽然有钱，但却不幸福。 -
• He tried hard but did not succeed. 他作了很大努力，但是没有成功。 - 2.
[用于否定词之后] -
• I never go past the house, but I think of him. 我走过那座房子时，没有一次不想起他。 -
• No work is so difficult, but we can do it. 不管工作怎样难，我们都可以做。 - 3.
[用于否定词加 deny，doubt，question 等词之后 相当于连接词 that] -
• There is no doubt but he will succeed. 毫无疑问，他会成功的。 - 4.
[表示可能性，相当于连接词 that] -
• It is ten to one but you lose. 你十有八九要输。 - 5.
[用于加强语气] -
• Good heavens，but it rains! 啊哟，下大雨了!