Using "Like" And "As If" In Unreal Conditions?

Question

1- Why do you talk about him as if he were an old man? (He is not an old man.)

2- They treat me as if I were their own son. (I'm not their son)

Can I use "like" in these sentences above instead of "as if" ? As:

1'- Why do you talk about him like he is an old man ?

2'- They treat me like I am their own son.

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3- I feel like I have run a marathon . (I am just too tired because I just run one kilometre. So I haven't run a marathon.)

4- You look like you have seen a ghost. (She is just so terrified. She didn't see a ghost.)

Can I use "as if" in these sentences, 3 and 4, instead of "like". If I can, should I use subjunctive mood or not?

3a- I feel as if I have run a marathon.

3b- I feel as if I had run a marathon.

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4a- You look as if you have seen a ghost.

4b- You look as if you had seen a ghost.

Answer 1

All of these forms will be often heard (and read) and may be created by fluent and native speakers. None of them can now really be called incorrect. Strictly speaking "like" is a simple comparison usually followed by a noun or pronoun. "As" or "as if" is a conjunction and is normally followed by a subject and a verb although often one is elided. This distinction is observed less and less often, and may well be obsolete in the future.

By that rule 1 & 2 correctly use "as if" and 1' and 2' are in violation, but few if any English speakers would object to 1' or 2'. And by that rule 3 and 4 should use "as" or "as if", not 'like, but here I think "like" flows better. I would favor the forms 3b and 4b over 3a and 4a, because the running or seeing is in the past, even if an unreal past, and a recent one.

In general, "I feel as if i had X" pretty much implies that I have not done X. Thus "I feel as if I had run a marathon -- because I have." has a humorous effect, because this implication is first believed and then overturned. A "garden path" sentence.

But none of these are likely to cause raise eyebrows, or confusion, on the part of any fluent speaker.

Answer 2

3a and 4a seem more felicitous, because their contractions (I've and you've) sound more natural. "Like he is" and "Like I am" are both natural.