Question

Fill in the blank with the most appropriate option
____ they rented it before you called?
a) How
b) Who
c) Did
d) Had

Answer 1

Hint: “How” signifies process, “who” signifies inquiry about someone, “did” and “had” signify enquiry about the doing of an action. “Did” is never used when there is already a past tense in the question. The question asked is: If the house was already rented before you called.

Complete answer:
The correct answer is option d. “Had they rented it before you called?” The term “had” here implies the job of renting out the house/room, etc. It is in the past perfect tense. Past perfect tense means that the main action is followed by another smaller action. In the given sentence, the main action is them renting out the house which is followed by an ancillary action of you calling them.
Option a is wrong because “How” needs to be followed by a helping verb to form a proper sentence.
Option b is wrong because once again, “who” needs to be followed by a helping verb. For example, Who did they rent it to before you called?
Option c is also wrong because “Did” cannot be used with the past tense “rented”. Past tense and “did” cannot be used in the same sentence.

Note:
 The best way to ace such questions is by placing the option in the given sentence and seeing it is grammatically correct. Many people make the biggest mistake of using “did” and another past tense in the same sentence. Once you are using “did”, there is no need to add a word with -ed in it again. The word “did” signifies that the sentence is in the past tense.