must表示推断

现在时 must+现在式：
He must live here．
他一定是住在这里。
或must+进行式：
He must be living here．
（译文同上。）
过去时 must+完成式：
He must have lived here．
他一定在这里住过。
或 must+ 完成进行式：
He must have been living here．
他当时一定住在这里的。
注意 must的各种过去式表示推断和 had to相当于 must表示义务的区别。 must不能用于表示否定的推断，一般也不用于疑问式，除非是对含有must的推断句提问：
—There is a lot of noise from upstairs．It must be Tom．
—Why must it be Tom？Other people use that flat．
—楼上喧闹的声音很大。一定是汤姆弄的。
—为什么一定是汤姆呢？那套房子里也有别人。
He has a house in London and another in Paris，so he must be rich．
他在伦敦有一栋房子，在巴黎又有一栋房子，可知他一定有钱。
—I've had no sleep for 48 hours．
—You must be exhausted．
—我已经48小时没睡觉了。
—你一定筋疲力尽了。
He develops his own films．That must save him a lot of money．
他自己冲洗照片。那样肯定为他节省了很多钱。
I keep meeting him on the bus．He must live／must be living near by．
我接连在公共汽车上碰到他。他一定就住在附近。
The police are stopping all cars．They must be looking for the escaped prisoner．
警察命令每一辆车都停下来（接受检查）。他们一定是在查找逃犯。
—What explosion？I didn't hear any．
—You must have heard it！The whole town heard it！
—什么爆炸声？我一点也没听见。
—你一定听见了！全城人都听见了！
He must have taken sleeping pills last night．He didn't wake up till lunch time．
他昨晚一定吃了安眠药。他一直到吃中午饭的时候才醒来。
—I waited under the clock！
—So did I，but I didn't see you！We must have been waiting under different clocks．
—我在大钟底下等的！
—我也是，可我没见到你！一定是在两个不同的钟底下等的。
—It was a head-on collision，but the drivers weren't hurt．
—They must have been wearing their seat belts．
—这次车祸中肇事车辆迎头相撞，但两个驾驶员都没伤着。
—他们肯定系了安全带了。