Question

It _____ rain today. There are so many clouds in the sky. Choose the correct word to fill in the blank.
(a)can
(b)has to
(c)may
(d)should
(e)mustn’t

Answer 1

Hint: Look for pointers suggesting which modal auxiliary to use in which blank. The sentence simply states a possibility. These pointers are indicators of certain
situations.

Complete answer:
Verbs are action words that show action (sing),
occurrence (develop), or state of being (exist), usually of a noun. Every sentence requires
a verb. The basic form of a verb is known as an infinitive. A modal auxiliary is a type of verb that is used to indicate modality – that is: likelihood, ability, permission, request, capacity, suggestions, order, obligation, or advice. Modal verbs always accompany the base form of another verb having relevant linguistic content.

In the given sentence, the narrator is telling us the fact that there are several clouds in the sky. This points to the fact that there is a strong possibility of rain. This means that the given blank should contain a modal auxiliary that indicates possibility.
Now, we know what we are looking for. Let’s look at the given options:
(a)can - This modal verb indicates ability. This verb does not fit into the given blank as it does not indicate possibility. This is not the required answer. So, this is an incorrect option.
(b)has to - This modal verb indicates compulsion. This verb does not fit into the given blank as it does not indicate possibility. This is not the required answer. So, this is an incorrect option.
(c)may - This modal verb indicates possibility, and therefore, this verb fits perfectly into the given blank and completes the given sentence. This is the required answer. So, this is the correct option.
(d)should - This modal verb indicates obligation. This verb does not fit into the given blank as it does not indicate possibility. This is not the required answer. So, this is an incorrect option.
(e)mustn’t - This negative modal verb also indicates moral responsibility and is suggestive of not doing something. This verb does not fit into the given blank as it does not indicate possibility. This is not the required answer. So, this is an incorrect option.

Note: We also use may: (a)when we are not sure about something in the present or future, (b)to ask for permission in a formal way or (c) to say that someone has permission formally.