Context 1: Suppose today is May 29, 2017

1. If John F. Kennedy was alive, he would have turned 100 today.

2. If John F. Kennedy had been alive, he would have turned 100 today.

Context 2: Today is Aug 14,2019

3. If John F. Kennedy was alive, he would have turned 103 next year.

4. If John F. Kennedy had been alive, he would have turned 103 next year.

Hi. Are all the above four sentences correct in the context? I make them up. Thank you.

Original Post

Hi, zuotengdazuo, and welcome to the G.E,

zuotengdazuo posted:

Context 1: Suppose today is May 29, 2017

1. If John F. Kennedy was alive, he would have turned 100 today.

2. If John F. Kennedy had been alive, he would have turned 100 today.

Context 2: Today is Aug 14,2019

3. If John F. Kennedy was alive, he would have turned 103 next year.

4. If John F. Kennedy had been alive, he would have turned 103 next year.

Hi. Are all the above four sentences correct in the context? I make them up. Thank you.

IMHO, sentence one is fine. It is what is called 'mixed conditionals'. John F. Kennedy isn't alive today, which means it is a counterfactual situation in the present, so you use the past simple (subjunctive mood). I see that the main clause here should be 'would turn', but 'would have turned' could also work if you mean at an earlier time today. You can write it like this:

If John F.Kennedy was / were live, he would turn / would have turned 100 today.

Sentence two doesn't work because of using the past perfect after 'if', which means you are thinking of a counterfactual situation in the past (subjunctive mood), while here you are thinking of the present. I mean that sentence could work if your supposition is related to the past. Today is 14th August, 2019. Then you can say:

- If John F. Kennedy had been alive in 2017, he would have turned .... today.

Sentences 3 doesn't work because of using 'would have turned ..' while you are thinking of the future.

Sentence 4 is meaningless.

BTW, your question reminded me of one Michael Jackson's songs called 'They don't care about us'. In one part of it, he says:

But if Roosevelt was living, he wouldn't let this be.

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Thank you very much. It helps a lot.

So can we say “If he was alive now, he would have turned 103 next year”?

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zuotengdazuo posted:

Thank you very much. It helps a lot.

So can we say “If he was alive now, he would have turned 103 next year”?

No, I don't think so. This a counterfactual (hypothetical) conditional in the present, which requires unreal past simple in the 'if' clause and 'would + inf.' in the main clause.

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zuotengdazuo posted:

Context 1: Suppose today is May 29, 2017

1. If John F. Kennedy was were alive, he would have turned 100 today.

2. If John F. Kennedy had been alive had not died, he would have turned 100 today.

Context 2: Today is Aug 14,2019

3. If John F. Kennedy was were alive, he would have turned would turn103 next year.

4. If John F. Kennedy had been were alive, he would have turned would turn 103 next year.

zuotengdazuo posted:

So can we say “If he was alive now, he would have turned 103 next year”?

No. You can say:

• If he were alive now, he would turn / would be turning 103 next year.
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Thank you very much for your explanation and correction, AHMED_BTM and David.

By the way, why can’t I like your replies?

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zuotengdazuo posted:

By the way, why can’t I like your replies?

When we transitioned to this new platform, a little over a year ago, I requested that the programmers disable the "like" function, so that there wouldn't be the sense of a popularity contest, comparable to Facebook and some other grammar sites. We prefer that members express their appreciation in words. Thank you.

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