It depends on how you use the word. If you use it as an adjective, pronoun, or conjuction, then it does not require a comma before it. For example, "Pull on either end of this string" (adjective); "There are two doors that lead to the exit; you can choose either" (pronoun); "Either say it now or come tomorrow" (conjunction). If you choose to use the word as an adverb, a comma is not necessarily required, but if you feel that you should pause before saying it, then add a comma. For example, "She didn't feel like she was qualified for it either" and "She didn't feel like she was qualified for it, either" are both acceptable, depending on if feel like you pause or not when saying it.
Or more tersely: only when it begins a clause. Commas are a feature of sentence structure. There is no word in English that requires a comma.
A comma is not required in the salutation of an editorial letter. You can use either a comma or a colon after the recipient's name. For example, "Dear Editor," or "Dear Editor:".
The general rule is that it doesn't need a comma before it. Example: I like apples as well as guavas.
Either a comma or a semi colon can be used, depending on the rest of the sentence.
I don't know what you're talking about. Sorry...
Yes, a comma is usually required before the phrase "formerly known as" to separate it from the rest of the sentence. This helps to clarify the transition from the previous name to the new one.
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.
It could go either ways?
No, a comma is not always required before "but" in a sentence. It depends on the structure of the sentence and the context in which "but" is used. If "but" is connecting two independent clauses, a comma is typically used before it.
No, it is not always required to use a comma before but. Usually the only time you will put a comma before the word 'but' is when you are separating two independent clauses.Examples of a sentence that doesn't require a comma:1. "We enjoy eating fish but not squid."2. "Everyone but Sally eats fish."
It depends on the context. It can be correct to put a comma before "then" or after "then", or not to have a comma either before or after "then". There is no word or phrase in English that requires a comma. Examples: Turn left at the light, then take the next right, and then take the second right after that. Let's eat dinner now, and then, if you'd like, you can play video games.
last comma before the and is not necessary
It depends on the context. For example a sentence could say, "I don't like it either." There is no comma.