核心问题
have (got) to 与 must 都表示“必须”的意思, 它们之间有没有区别呢?
词典解答
must 着重表示“说话人或听话人自身的义务”，带有较重的个人色彩（个人的责任感、自觉性）。有时则含有讲话人行使权威的意思。
-
I must do what you tell me. 我一定照你说的办。
-
You must come and visit me. (Collins) 你必须来看我。
-
You must be back by ten o'clock. (“You are obliged to be back...”; “I require you to be back...”) (CGEL) 你必须10点以前回来。 have (got) to 则着重表示“由客观条件所引出的义务”，缺少个人主观色彩，因此，语气比 must 更强。
-
I have (got) to go now. 我现在该走了。(可能另有约会等等)
-
We have (got) to send these VAT forms back before the end of the month. (LEG) 我们必须在月底前把增值税表送回。(法律要求这样做)
-
I've got to do something! Langdon thought. (Dan Brown, The Da Vinci Code) 兰登想：“我得做点什么！”(《达·芬奇密码》)
(参见 must/have to)