Question

When I saw him, he ____________ a computer.
was using
has been using
uses
used

Answer 1

Answer:

was using

Explanation:

when I saw him he was using a computer change it into hindi

Answer 2

The blank can be filled with the word 'was using'

So, correct option is (1) and correct sentence will be

When I saw him, he was using a computer.

The selection of option is based on the tense of the sentence.

We can detect whether the sentence is in future, past or present tense by looking the structure of the given sentence.

Here it is in past as 'saw' is used which is V2 form of see. Past form of verb will be used.

As there must be a continuous action which he saw so there will be used past continuous tense sentence structure.