i. Must
-
Function of Must in obligation
1. To express the idea of necessity or unavoidable obligation, or a condition
which cannot be changed.
E.g.: The time is up. We must go.
Perhaps we do not want to, but we have to choice
One must eat to live.
There is no choice
You say you want to pass. Then you must try harder.
it is the only way 2.
Must in the negative express prohibition and is used to keep someone
from doing something. The prohibition may be because of a rule, a law, the general disapproval of society, or the danger involved.
E.g.: You must not walk on the grass. There is a rule against it You must not pick the flower in the park.
It is prohibited by law You
mustn’t smoke in class.
Children
mustn’t cross busy streets alone.
Must can only be used to refer to present and future obligation. To talk about the past, had to is used.
E.g.: I had to leave early because I wasnt feeling well. 3.
In affirmative, must can be used to give strong advice or orders to oneself or other people.
E.g.: I really must stop smoking. You must be here by eight oclock at the latest.
When must is used the obligation comes from the speaker. If the obligation comes from outside must is possible but HAVE TO is more
common. E.g.: I have to work from 9.00 a.m. till 5.00 p.m.
4. In interrogative, must is used to ask about the wishes or intentions of the
person one is speaking to.
E.g.: Must I clean all the rooms? Why must you always leave your dirty clothes in the bathroom?
59
-
Function of Must in deduction
1. Must can be used to say that we are sure about something because it is
logically necessary. E.g.: Mary must have some problem: she keeps crying.
Im in love. That must be nice. Theres the doorbell. It must be Roger.
2. Must is only used in this way in affirmative sentences. In questions and
negatives we use can or cant instead. E.g.: That cant be the postman. Its only seven oclock.
What do you think this letter can mean? 3.
Must is used with the perfect infinitive for deductions about the past. can and cant for questions and negatives
E.g.: We went to Majorca. That must have been nice. The lights have gone out. A fuse must have blown.
I dont think he can have heard you. Call again. Where can John have put the matches?
He cant have thrown them away. 4.
In reported speech, must can be used after a past reporting verb as if it were a past tense. Only in that case, must refers to the past.
E.g.: I decided that I must stop smoking. I felt there must be something wrong.
60
j. Ought to
1.
Ought to, like should, express desirability, avoidable obligation, or duty. It relates to present or future time. Ought to and should are often used
interchangeably.
E.g.: You ought to study more. If you want to learn
59
http:ismailmidi.comberita-168-must-vs-have-to.html
60
http:ismailmidi.comberita-168-must-vs-have-to.html
Kategori