Question

Fill in the blank with a suitable modal:
Geoff works too much. I think he _________ take it easy.

• A. must
• B. have to
• C. should
• D. don't have to

Answer 1

The correct option is C should

Answer : C

Let's take a look at the usage of the modal verbs in the options:

• must : to express a necessity (in the present or future); to make an assumption that something is true
• have to : It is used to express an external obligation in positive sentences and removing an external obligation (or necessity) in the negative sentences
• should : It is used for expressing an opinion / advice / expectation / criticism about some past action or it can be used to ask for an advice

• don't have to : It is the negative form of 'have to'; it is used to remove necessity or external obligation

Here in the question, we see that the speaker is expressing an opinion that Geoff should take it easy.

• As it is an opinion that is expressed and not a necessity or external obligation -- therefore 'have to' & 'must' are not suitable here.
• 'don't have to' is not suitable either because Goeff needs to take it easy but he definitely has an obligation to work, and moreover it would mean that he doesn't have to take it easy which is contrary to the opinion intended to express by the speaker.

Therefore from among the options, 'should' is the most suitable verb to complete the sentence.

Thus, the correct complete sentence is:

Geoff works too much. I think he SHOULD take it easy.