It could follow a comma, which would be fairly common.
It could follow quotation marks, "Which cake would you like?"
None, open punctuation means there is no punctuation after the salutation or the complimentary close.
The correct punctuation for "which" would depend on its usage in a sentence. It could be followed by a comma if introducing a nonrestrictive clause or used without punctuation for a restrictive clause.
This is not a single punctuation with a separate name. It signifies a question asked in an exclamatory way.
A colon typically comes before a list or explanation. It is placed at the end of the sentence, followed by a single space and then the first item or explanation.
comma
The correct punctuation for "Are you there yet?" she asked is to add a question mark after "yet" and keep the tag question in lowercase followed by a comma.
It is a command, likely followed by an exclamation point. "Hit the brakes!"
A colon is typically used after "P.S." in a letter or message, followed by the additional content.
True
true
No, a comma is not needed after "In this case" unless it is followed by a clause or parenthetical element that requires punctuation.
Yes, in mixed punctuation style, the complimentary close is followed by a colon.