No. A comma precedes "such as" when what follows is an example of whatever went before. In this case, it is nonrestrictive. (For nonrestrictive constructions: use a comma.)
Example
My favorite flavors of candy are fruit flavors, such as cherry and lemon.
The sentence is complete and the idea is complete without the list of specific instances. The list just illustrates the meaning of "fruit flavors" but does not restrict it. So it is nonrestrictive and needs a comma.
You don't use a comma before "such as" when what follows defines or limits what went before. In this case it is restrictive. (For restrictive constructions: no comma.) Example
The refugees were unable to carry things such as clothes, bedding, and furniture.
Here, what comes after "such as" serves to define (restrict) the idea of "things." The category isn't named. The list is necessary to explain what kinds of things the refugees had to leave behind. The category might be "household goods," but it isn't stated--instead, the "such as" list supplies the definition. It is restrictive. No comma.
(It would be better English to say "such things as...," but this wording stresses the parallel example.)
If you rewrote this sentence to name the category, you would then not need the comma:
The refugees were unable to carry their household goods, such as clothes, bedding, and furniture.
A comma is typically used before "such as" when introducing examples in a sentence. However, there are cases where the comma may not be necessary depending on the structure and flow of the sentence.
A comma does not always come before the phrase such as. A comma is only used in front of such as if it is a part of a non-restrictive clause.
Yes....
No, a comma before "as appropriate" is not necessary. It depends on the context of the sentence and whether it flows better with or without the comma.
No, a comma does not always come before "for instance." It depends on the structure of the sentence. A comma is typically used before "for instance" when it introduces a non-essential or parenthetical element in the sentence.
Not at the beginning of a sentence. As you know is a clausal sentence adverbial, and as such it should generally be set off by punctuation. That would mean a comma after it at the beginning of a sentence, a comma in front of it at the end of a sentence and commas on both ends when it appears in the middle of a sentence: "He is, as you know, rather obstinate."
No, a comma is not always necessary before "which" in a sentence. Use a comma before "which" when introducing a nonessential clause, but do not use a comma before "which" when introducing an essential clause.
No, a comma before "but" is not always necessary. It is typically used before coordinating conjunctions like "but" when joining two independent clauses. If the clauses are closely related and short, a comma may be omitted.
Yes
No, a comma before "as appropriate" is not necessary. It depends on the context of the sentence and whether it flows better with or without the comma.
No, a comma does not always come before "for instance." It depends on the structure of the sentence. A comma is typically used before "for instance" when it introduces a non-essential or parenthetical element in the sentence.
No. There is no word in English that always requires a comma before it.
Sometimes, but not always. There is no one single rule that applies to "but." ----
Not at the beginning of a sentence. As you know is a clausal sentence adverbial, and as such it should generally be set off by punctuation. That would mean a comma after it at the beginning of a sentence, a comma in front of it at the end of a sentence and commas on both ends when it appears in the middle of a sentence: "He is, as you know, rather obstinate."
It depends on the type of sentence. So your answer would be not all the time. I hope that helps! :)
No
A period should come before the footnote at the end of a sentence, while a comma should not.
,Always.
No, definitely not. In very many cases it would not even be optional. It would simply be wrong.
As always, I enjoyed my time with the kids.