Question

I think he'd be happer if the .... alone.( not live) second conditional)​

Answer 1

Ответ:

I think he'd be happier if he didn't live alone.

Конструкция:

(If + Past Simple) + (would + V)

Answer 2

Ответ:

I think he'd be happier if he didn't live alone.

Answer 3

I think he'd be happier if he were left alone.

In the given sentence, the second conditional is used to express a hypothetical or unreal situation. The phrase "if he were left alone" suggests that the person in question would experience more happiness or contentment if they were not accompanied or disturbed by others.