Special uses of auxiliary verbs
The auxiliary verb must can be used to express probability or inference.
She must be about fifty years old.
You must have been mad to do such a thing.
She must have received your letter.
Note that in the sentences given above, must does not express compulsion or obligation, but inference.
I suppose he is the oldest man in the village. (= He must be the oldest man
in the village.)
I think she is older than her husband. (= She must be older than her
Can be + adjective
Read the following sentences.
He can be very annoying. (= He is not always annoying, but occasionally he is.)
She could be very intrusive. (= She is not always intrusive, but occasionally she is.)
Father can be very stern. (= Father is very stern at times.)
Do a lot of + gerund
This structure is used to emphasize the frequency with which we perform an action.
He does a lot of traveling. (= He travels a lot.)
I don’t do much traveling. (= I don’t travel much.)
I used to do a lot of gardening.
I have no time to do much gardening these days.
This old woman does a lot of talking. (= This old woman talks too much.)