Question

Fill in the blank with the most suitable option:
A: His office is empty. He must have gone home.
B: But his briefcase is here. He_________ home.

A. Might not go
B. Couldn't have gone
C. Ought not to go
D. Could have gone

Answer 1

Hint: A Modal verb is a type of verb used to denote modality, i.e. possibility, ability, permission, request, ability, suggestions, order, duty, or advice. The base form of another verb that has semantic content is often followed by modal verbs.

Complete answer:
It is Choice B that is the correct answer.
COULDN'T HAVE GONE is used to show an event's certainty. The speaker says in the given sentence that since the briefcase is here, it is clear that, while the office is vacant, he has not gone home. Thus, the correct answer is option B.

The choices remaining are incorrect because:
Chance is represented by ‘Might NOT GO.’
‘OUGHT NOT GO ‘reflects responsibility.
Could Have GONE states that he has gone home, but the statement tries to say the exact opposite and convey it.

Additional Information:
Modals are special verbs that behave irregularly in English (also called modal verbs, modal auxiliary verbs, modal auxiliaries). They vary from standard verbs such as "job, play, visit ..." They provide additional details about the main verb 's function that follows it. They have a wide range of communicative positions.
Here are some features that modal verbs have:
1. They never alter their shape. You would not be able to add "s", "ed", "ing" ...
2. They are often preceded without "to" by an infinitive (i.e. the bare infinitive.)
3. They are used to indicate modality that allows speakers to express certainty, choice, willingness, duty, need, capacity.


Hence the correct answer is option ‘B’

Note:To answer this type of question you need to develop the basic understanding about the common modal verbs. Here is a list of modal verbs:

Can, could, may, might, will, would, shall, should, must
The verbs or expressions dare, ought to, had better, and need not behave like modal auxiliaries to a large extent and may be added to the above list