Question

You have been away for a while and have just come back to your home town. You meet Gerry, a friend of yours. He asks you a lot of questions:
Gerry: How are you?
Now you tell another friend what Gerry asked you. Use reported speech.
a. He asked me how long had I been back.
b. He asked me how long I have been back.
c. He asked me how long I had been back.
d. He asked me how long have I been back.

Answer 1

Hint: Simple present tense sometimes gets converted into simple past tense in indirect speech, as it is a reported form of speech. It is not the exact quote someone said.

Complete answer:
In grammar, there are two types of speech that are recognized - direct and indirect.
In direct speech, the sentence is written exactly as the person said it. However, in indirect speech, a third person repeats the sentence that was originally said, so there are many changes in the sentence.
From direct speech to indirect speech, the tense has to be changed from present to past. When you convert a sentence from direct to indirect speech, the tense has to be changed
compulsorily. So, to change the speech here, we must change it to simple past tense. As it is a question, in indirect speech, the word order goes back to normal, i.e. the subject comes before the verb.

Now we know what we are looking for from the options. Let’s look at the given options-
a. He asked me how long had I been back. - In this option, the tense is correct, however, the order of the question has not been changed. This is not grammatically correct. This is not the required answer. So, this is an incorrect option.
b. He asked me how long I have been back. - In this option, the order of the question has been changed, however, the tense is incorrect. This is not grammatically correct. This is not the required answer. So, this is an incorrect option.
c. He asked me how long I had been back. - In this option, the tense and the order of the question are correct. This is the required answer. so, this is the correct option.
d. He asked me how long have I been back. - In this option, the tense is incorrect, and, the order of the question has not been changed. This is not grammatically correct. This is not the required answer. So, this is an incorrect option.

Note:
Identify the grammatically correct and the most contextually sound option. There are certain rules to be followed for converting direct speech to indirect speech in order for it to be grammatically correct.