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