Question

Fill in the blank with a verb that agrees with the subject and not with the complement:
Rachna _____ know the answer despite the fact that she is the most intelligent of all. [Basic]

• A. doesn't
• B. don't
• C. isn't
• D. hasn't

Answer 1

The correct option is A doesn't

In order to fill in the blank with the most appropriate helping verb, we must understand the 'subject and verb agreement'. A subject is a person, thing, or a concept, in a sentence. A sentence always describes a person, thing or a concept and that is called 'subject' of the sentence. The rest of the sentence is a complement (which has the object in it). A subject and a verb should always agree in a sentence. If the subject is singular (example: Raj), the verb will also be singular (does). If the subject is plural (We), the verb will also be plural (do).

As the given sentence asks us to fill in the blank with a verb that agrees with the subject and not with the complement, we will focus on the subject only.

Option B - 'Don't' is a plural verb, which can be used with a plural subject only. As the given sentence has a singular subject, we can't use 'don't' here. Hence, option B is incorrect.

Option C - 'Isn't' is a singular verb, but it can't be used here, as 'isn't' can only be used as a main verb in such sentences. Here, the main verb is 'know' and that's why it is grammatically incorrect to use 'isn't'.

Option D - 'Hasn't' is a singular verb, but it can't be used here. As the main verb 'know' explains to us, the sentence is in simple present tense. If we use 'has' with a verb, it becomes present perfect tense. Hence, option D is incorrect.

Option A - 'Doesn't' is a singular subject and can be used with a verb in its original form. As it matches the tense of the sentence and agrees with the subject, we can use 'doesn't' here. Hence, option A is the correct answer.

'Rachna doesn't know the answer despite the fact that she is the most intelligent of all.'