I agree with what Mganjoo has pointed out so clearly in the post above. These sentences are normally called "if clauses", so I do not understand what difference is meant by User 20119 when he mentions "hypothetical" sentences as being different.

I would also add a different construction, in which you indicate the outcome of a past action, that is to say something which would not be true now if something else had not previously happened. An example of this is

If my grandfather hadn't emigrated to the United States, I wouldn't be living in Seattle

(if he had stayed in his native country, I would have been born there and would be living there too). In this case you have a conditional form in the main clause and a Past Perfect tense in the hypothesis, which may be introduced by if or may present subject-verb inversion with no difference in meaning.

I agree with what Mganjoo has pointed out so clearly in the post above. These sentences are normally called "if clauses", so I do not understand what difference is meant by User 20119 when he mentions "hypothetical" sentences as being different.

I would also add a different construction, in which you indicate the outcome of a past action, that is to say something which would not be true now if something else had not previously happened. An example of this is

If my grandfather hadn't emigrated to the United States, I wouldn't be living in Seattle

(if he had stayed in his native country, I would have been born there and would be living there too). In this case you have a conditional form in the main clause and a Past Perfect tense in the hypothesis, which may be introduced by if or may present subject-verb inversion with no difference in meaning.