Usually an ellipsis is used ( . . . ) ; see related link .
If you mean "do we use a comma before 'etc.'?", then yes we do. Remember to take some paper, a pen, etc. (Oxford ALD).
No. Usually in a list there is/are no comma(s). The list would instead go something like this: Mum's Shopping List: #Bread #milk #soup etc, etc.
Yes. Example: They used many different building materials including wood, metal, stone, etc. Not necessarily. There is no word or phrase in English that requires a comma before or after it.
Sequence F(n): -3/2,5/4,-7/6,9/8,-11/10,etc F(n) = (-1)n(2n+1)/(2n)
Twice, with a comma before and between, like this: The frumpy lecturer went boringly on and on ad infinitum and even beyond, etc, etc.
No.
No. After the word and comma can not be used, as it is grammatically inappropriate to use comma after conjunctions such as and, which are called coordinate conjunctions.
Not necessarily. There is no word or phrase in English that requires a comma. For example: we went along with the plan, or he brought me along with him etc. When it means "in addition to," its entire phrase may be set off with a comma. For example: Along with tasting bad, it was also ugly, or It was ugly, along with tasting bad.
No, a comma is not necessary.
you need a period because etc. is an abbreviation for etcetera.
Either a period ( . ) or an ellipsis ( . . . ) will go after 'etc' .
no