It could depend on what it is you are trying to say, but as it is it is grammatically correct.
Both; for is a person & of would be for something besides.
Yes, it is. For example, "I am thankful for the support of my friends and family."
The phrase "support to" is not grammatically correct in standard English usage. The correct construction is typically "support for" when referring to providing assistance or backing to someone or something. It is important to use the appropriate preposition to convey the intended meaning accurately.
No, it is not grammatically correct. The correct way to say it is "your older sister."
yes you could say which is better or worse
It is grammatically correct to say: There is nothing wrong with this machine.It is not grammatically correct to say: Will it is be grammatically correct to say ....The correct way to write that or say that would be: Would it be grammatically correct to say....
The latter form is grammatically correct but the former is in popular usage.
What exatly am I supposed to be squinting at is grammatically correct or, you could say at what am I squinting exactly.
No, the phrase "it is well" is not grammatically correct. It seems to be missing a verb or adjective to complete the sentence. You could say "It is well done" to make it grammatically correct.
No. It is grammatically correct to say, "I admire you, greatly."
'What a drunkard you are' is a grammatically correct English sentence.