Question

Fill in the blanks with the appropriate modal auxiliary:
Please don't tell anybody what I said
Don't worry I ___________.
a) Shouldn't
b) can't
c) won't
d) must

Answer 1

Hint: A modal auxiliary is a verb that is used with another verb. Examples of such words are: must, can, should, shall, will, etc. In the given sentence we have to use a modal auxiliary which is in the negative. The given sentence implies that I will not tell anybody what you have told me.

Complete answer:
Option a is wrong because I shouldn't imply that out of moral reasons, I should not tell what you told me which is not exactly the meaning which is being tried to be portrayed here.
Option b is wrong because I can't tell anybody means I want to tell but I cannot because of certain obligations and reasons.
Option c is the correct answer because Don't worry I won't tell anybody what you said implies that I am not going to say it because it is out of my own will that I won't say it.
Option d is wrong because like shouldn't mustn't also means that I can't tell others because I am being forced to not tell anybody.

Note:
 Modal auxiliaries usually portray the mood of a sentence. Therefore, it is important that you use logic while deciphering the meaning of the sentences. Such words do not usually have rules so you have to understand the meaning of the given options. Use it in the sentence and see if it is correct.