▲这位网友的看法基本上是对的。must 表推测时，其后通常是接状态动词，如 be, have, know, feel 等。如：

If this is true, that must be false. 如果这个是真的，那个必然是假的。

He must be the best violinist alive. 他一定是当代最好的小提琴手了。

You must feel tired after your long walk. 在走了好长一段路之后，你一定感到累了吧。

You can eat all this. You must have a good digestion. 你能吃这么多，你的消化力一定很强。

Certainly they must know the result of such speeches. 肯定他们一定知道这样言论的后果。

▲如果不是表示状态的动词，则通常会改用其他说法来表示肯定推测。比如：

1. be sure to do sth

They’re sure to welcome you with open arms. 他们一定会热烈欢迎你。

This is sure to be an item on the agenda next week. 这一定会成为下星期议事日程上的一项议题。

Anyone who goes food shopping without a list is sure to forget the things they really need. 任何人如果采购食物时没列清单的话，肯定会忘了真正需要的东西。

2. be certain to do sth

However, the scheme is certain to meet opposition from fishermen’s leaders. 然而，这项计划一定会遭到渔民领袖的反对。

If they followed the road, they would be certain to reach a village. 如果他们沿着这条路走，就一定会到达一个村庄。

The company is certain to reinvest its profits productively. 公司肯定会将它的利润进行高效益的再投资。

3. will definitely do sth

It would be tempting fate to say that we will definitely win the game. 要说我们肯定会赢这场比赛，还真有点冒险。

This book will definitely appeal to teenagers and young adults. 这本书肯定会吸引青少年。

4. will certainly do sth

If the conservatives are not removed, then the party will almost certainly split down the middle. 如果不除掉保守势力，那么这个党几乎肯定会分裂成两派。

Direct questions would almost certainly result in evasive answers. 直接的提问得到的几乎肯定会是含糊其词的回答。

5. will surely do sth

Where eastern Germany goes the rest will surely follow. 东德怎样做，其他地方一定会效仿。

The government will surely use the diplomatic channels available. 政府肯定会利用各种现有的外交渠道。

Herbert would surely advise her how to approach the bank. 赫伯特一定会就如何与银行接洽向她提供意见。

6. be bound to do sth

We are bound to face criticism from both sides. 我们肯定会面临来自两方面的批评。

I’ll show it to Benjamin. He’s bound to know. 我会把它给本杰明看，他肯定会知道。

They will react with hostility to the price rises and calls for equivalent wage increases are bound to be heard.  他们将会强烈反对价格上涨，同时肯定会要求相应地增加工资。

▲当然，用 must 后接动作动词也不是完全不可以，只是比较少见。如以下句子均摘自词典：

If we keep going upwards we must get to the top. 如果我们继续向上走，就一定能到顶上。

Damage is the gist of the action and without it the plaintiff must fail. 造成损伤是这次诉讼的要点，不抓住它原告必定失败。

……

▲但是，如果 must 接动作动词用进行式或完成式来表示推测，则完全属于通常的用法。如：

You must be joking. 你准是在说笑话。

He must be writing a letter to his girl friend. 他一定在给他女朋友写信。

I must have caught a cold on the bus. 我一定是在公共汽车上染了感冒。

I must have read that in some book. 我一定是在某一本书上读过这个的。

Rebuilding the house must have cost a small fortune. 重建这座房子一定花掉了不小的数目。