Question

Complete these sentences using the appropriate modal auxiliary:
The situation is serious. Something ___ be done before it's too late.
A. Must
B. May
C. Shall
D. Will

Answer 1

Hint: The correct option to be chosen should be a modal verb. It is always used along with an infinitive. As the given sentence suggests, the situation is serious. Choose the option that would fit well while signifying something necessary.

Complete answer:
The basic definition of a modal auxiliary means verb which is used with another verb in order to express a mood or tense. Examples of a modal auxiliary are- can, may, must, ought, shall, should, will and would.

Option A is absolutely the correct answer. 'Must' is the correct modal verb that fits right in the given sentence. A Modal verb refers to a type of verb which is used to indicate modality in general.
For example : likelihood, ability, permission, request, capacity, suggestions, order, obligation, or advice. Modal verbs have a thumb rule of accompanying the base form of another verb which has a semantic content. The modal verb 'must' is preferred while indicating or expressing obligation and necessity. As, the sentence suggests, Option A is the most suitable answer for the same.

Option B is wrong. 'May' is a modal verb. But it is not appropriate to use this verb in the sentence.
The modal verb may is used while asking, granting or describing permission; to politely offer to do something for someone; to show the possibility of something happening or occurring; or to show a wish or desire that something will be the case in the future. Hence, it is irrelevant to use this Option in the sentence given.

Option C is also incorrect. 'Shall' also comes in the category of modal verbs. However, the use of this verb, if used in the given sentence would spoil the literal meaning of the sentence.
This verb is used to indicate a future action. It is mostly used in sentences with "I" or "we," and is often found in suggestion. Thus, it's clear that Option C is not suitable.

Option D is also the incorrect answer. 'Will' is particularly very flexible and has several different functions and meanings. However, it's not appropriate to use this verb. As already mentioned, Option A is correct and all the other options are wrong.

Therefore, the correct answer is option ‘A’.

Note: Modal verbs add meaning to the main verb in a sentence by expressing possibility, ability, permission, or obligation.
Three basic rules to follow while using these verbs are as follows -
1)Use the modal verb as it is. Don't change its form and turn it into the present, future, or past forms. 2)Use the base form of the verb after a modal. Don't use “to” or the full infinitive verb “to”.
3)If you need to use modals in the negative form, then use only “not” after the modal verb.