Which one is right, "if you have any questions" or "if you have any question"? This clause will be used at the end of an email. The whole sentence is "Please don't hesitate to write to me if you have any ..." I am really confused by the singular or the plural form of the noun after the word "any". Which form is standard English? Why?

Seriously, is it grammatically correct saying "for what?" I received my friends message which said "I am quite happy." Then I replied her "for what?", but she replied "It is incorrect. I mean the grammar. You can use 'because of what', but you cannot use 'for what' and it is Chinglish." She pretty insisted that I was wrong, but I thought otherwise. Serious, am I wrong? Why?

"in group", "in a group" or "in the group"? Here is a sentence: Wild pigs have great courage and strength in __ group. Which one should be filled in the blank, "a", "the" or nothing? And why? Thank you for your answer!!!

After done/After being done, Subjective + be ... After hit, his face was swollen. After being hit, his face was swollen. Are there any differences between those two ways of expression above? If there are, then what are they?

After cured, I was full of green spark again. What I wish to know are: A. What does the phrase "green spark" mean? Is this an idiom? If not, then is this phrase belonging to native English? B. How about "After being cured, I was ..."? Should be the word "BEING" exist in this sentence, and why? If not, then what's the difference between those two ways of expression?

The "special" meaning of "wood" Does the word "wood" have some meanings related to sex? If has, then what are they?

Why it doesn't use question mark in the end? Here is the sentence: "Recurring Minor Issues, are they dangerous" from the website http://www.sevenforums.com/general-discussion/142888-gremlins-recurring-minor-issues-they-dangerous.html My question is: why doesn't this sentence put a question mark in the end? "are they dangerous" seems as a question, but why it isn't?