Question

Correct the underlined word if necessary:
She said she may join us for dinner.
  (A) NO CHANGE
  (B) could
  (C) might
   (D) can

Answer 1

Hint: A complete sentence is correct only if you are applying grammar rules correctly. A modal verb is a type of verb that expresses necessity or possibility - that is likelihood, ability, permission, request, suggestion, obligation. English modal verbs are shall, will, should, would, can, could, may, might.

Complete answer:
In the above question, we are talking about the possibility of a situation happening.
We use modal verbs to show if we believe a situation is certain, possible, or impossible. For example- My books must be in the cupboard. That can’t be Ellie’s dress.
We also use modal verbs when asking permission, ability, make requests, offers. For example- She can’t swim. May I come in?. Would you like some help?.
The given sentence is in indirect speech. Might express possibility. In the above sentence, the situation is about the possibility of joining them for dinner. While changing the speech from direct to indirect speech the tense is changed to past tense. Therefore, option(C) is correct.
Could express the ability of the situation and is an indirect speech of ‘can’ since the question is not talking about ability, option (B), and option (D) is incorrect.
May is used to referring to the present situation means present tense, Might is used to refer to the past and future tense. So, option (A) is incorrect.
Therefore, the correct modal verb with the question is might.

Note:
 Modal verbs are used in the situation of ability, possibility, permission, request, suggestion, likelihood, obligation. English modal verbs are can, could, shall, should, may, might, will, would. A might modal verb is used to express the possibility of a situation in the past and future tense. For example- It might rain tomorrow. So, the correct answer is an option (B)- might She said she might join us for dinner.