A) No.
B) I would try to avoid using the word however at the end of a sentence, as it is usually used to introduce a clause which contradicts something which has already been said, or is a relative adverb - and ought to precede that to which it relates.
Yes, typically a comma is used before the word "however" when it is at the end of a sentence to indicate a pause. For example: "I wanted to go to the party, however, I had to study for my exam."
It really depends on the context but it's not uncommon for commas to be used.
Yes
When using the word "however" in the middle of a sentence, you use commas before and after the word if combining a independent and dependent clauses. You may also use it for two independent clauses or use a ";" before the word however followed by a comma.
In a compound sentence, the comma would be placed before the word but.
I do not use a comma before and after that word, therefore you will not see it in any sentence I have written.
Yes, a comma should be used after the word "however" when it is used in the middle of a sentence to indicate a contrast or transition.
If the word 'however' is in the sentence, commas should be placed on both sides. Eg: Blahblahblah, however, blahblahblah. If,however, the word 'however' opens the sentence, the comma should only be placed after the word. Eg: However, blahblahblah.
Depending on what the sentence is about you may use a comma before 'called';however, in some instances you may not be allowed to place a comma before the word called.
When using the word "however" in the middle of a sentence, you use commas before and after the word if combining a independent and dependent clauses. You may also use it for two independent clauses or use a ";" before the word however followed by a comma.
Before
In a compound sentence, the comma would be placed before the word but.
Say your sentence aloud. If you find you pause before the word 'therefore', you will probably want to insert a comma. If you do not pause, no comma is required. Use a comma when the sense requires it, not because you have a specific word in your sentence.
If the word 'however' is in the sentence, commas should be placed on both sides. Eg: Blahblahblah, however, blahblahblah. If,however, the word 'however' opens the sentence, the comma should only be placed after the word. Eg: However, blahblahblah.
Not necessarily. Commas are a feature of sentence structure. There is no word or phrase in English that requires a comma.
Yes, typically a comma is placed before the word "unless" when it is used to introduce a dependent clause in a sentence. This helps to clarify the relationship between the main clause and the conditional clause.
I do not use a comma before and after that word, therefore you will not see it in any sentence I have written.
The comma goes before the word "but." For example: I was going to spell the word "comma" right, but then I fell into a coma.
No you don't.
It depends on the sentence.