Question

Fill in the blank with the most suitable option:
If you want to keep fit, you ___________ do some yoga.

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

Answer 1

Answer: (C)

should

Answer : C

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

• shouldn't : It is the contracted form of 'should not'; it is the negative form of the modal verb 'should'
• must : to express a necessity (in the present or future); to make an assumption that something is true; to express an opinion about something that is logically very likely
• 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"; & is used to express that something is not a necessity / obligation; & is used to express absence of an obligation or necessity

Here in the question, we see that the speaker is expressing an advice to do some yoga in order to stay fit.

Therefore from among the options, 'should' is the most suitable verb to complete the sentence, as it is used to express advice. (Also "should" is used in the construction of positive sentences and is used in First Conditional Sentences.)

• "shouldn't" is used to convey a negative advice and NOT a positive one, therefore it is NOT suitable here.
• must to : It is grammatically wrong, "must" is NOT followed by "to".
• "don't have to" is used to remove a necessity & is NOT used to express an advice -- therefore it is also NOT suitable here.

Thus, the correct complete sentence is:

If you want to keep fit, you SHOULD do some yoga.