E.g. If I may say so, I think you have treated him very badly

§ 86. In addition to the above cases illustrating the independent use of may, this modal verb occurs in subordinate object clauses after expressions of fear as well as in adverbial clauses of purpose and concession. Here it is structurally dependent (for a detailed treatment of this use of may see "Verbs", §§ 135, 143, 152).

e.g. I fear he may fall ill.

He is coming here so that they may discuss it without delay. However cold it may be, we'll go skiing.

Must

Must has the following meanings:

1) obligation (from the speaker's point of view),

e.g. You must talk to your daughter about her future.

In this meaning must is found in affirmative and interrogative sentences and followed only by the simple infinitive.

Prohibition,

e.g. He must not leave his room for a while. (Он не должен/ему

нельзя выходить из комнаты некоторое время.) This meaning is expre ssed in negative sentences and must is also followed by the simple infinitive.

Emphatic advice,

e.g. You must come and see us when you're in London.

4) supposition implying strong probability,

e.g. He must be ill. He looks so pale.

Must in this meaning is found only in affirmative sentences.

In Russian this meaning is generally rendered by means of the attitudinal adverbs вероятно, должно быть.

In English this meaning may also be expressed by means of the attitudinal adverb probably.

In this meaning must may be followed by different forms of the infinitive. If reference is made to the present, the Continuous infinitive is used with dynamic verbs.

e-g. The book is not on the shelf. Jane must be reading it. Let's have something to eat. You must be starving.

If must is followed by the simple infinitive of dynamic verbs, it expresses obligation.

e-g. Jane must read the book. You must stay here.

However, with stative verbs the simple infinitive is used to express supposition.

e.g. He must be over fifty.

Must + Perfect infinitive = the ac- tion to the past.

e.g

It is six o'clock. She must have come home.

must + Perfect Continuous infinitive = action begun in the past and continued into the moment of speaking.

e.g. It must have been raining all the night. There are big puddles in the garden.

However, if must is followed by a stative verb, the Perfect infinitive is used.

e.g. He must have been here since breakfast.

When must expresses supposition implying strong probability, its use is restricted in two ways:

a) It is not used with reference to the future. In this case we find attitudinal adverbs in the sentence.

e.g. He will probably come tomorrow. He will evidently know all about it.