The main rule of a comma is to use it to separate the elements in a series of three or more things. You should also use a comma to set off quoted elements and to separate coordinate adjectives.
I believe that when you have an appositive in a sentence that when it is not necessary you surround it with commas and when it is necessary, you don't use commas. This is what I believe the rule is, but I am not 100% sure. Anyone feel free to correct me if this is in any way not correct.
The commas between numbers in place value are commas.
Googol has 33 commas.
Putting too many commas, putting commas on the wrong places and puting no commas.
no 4 commas 1,000,000,000,000
That is a general rule, but there are exceptions to virtually every rule. It would be better to avoid such commas.
grammatical commas are something that is used with phrases
I believe that when you have an appositive in a sentence that when it is not necessary you surround it with commas and when it is necessary, you don't use commas. This is what I believe the rule is, but I am not 100% sure. Anyone feel free to correct me if this is in any way not correct.
I was always told as a rule to place them wherever you would take a breath or pause when you read the sentence aloud.
7 commas
A person with two commas is a millionaire. 1,000,000. Count them. Two commas.
The commas between numbers in place value are commas.
Googol has 33 commas.
Putting too many commas, putting commas on the wrong places and puting no commas.
a comma sandwich is something that has 2 commas in.
A sentence with three commas may be a complex sentence with multiple dependent clauses separated by commas.
Although some of these might seem quite obvious, here are the four main rules that I can think of: Commas are always used in lists of things. Example: I like to eat chocolate, steak, pavlova, ice cream and chops. Commas are either used in lists (like the above example), or when you are saying a sentence and need to pause or take a breath in the middle of it. Commas always come straight after a word, never a space and then the comma. Example: word, is correct. word , is not correct. This is a fairly new rule that was introduced a few years ago, which a lot of people don't actually use: There is never supposed to be a comma in front of the word 'and', as the word 'and' is supposed to be a pause within itself, although most people do not pay attention to this rule. Example: I like turtles, dogs, horses, dolphins, and cats. -This sentence would not be 'gramatically correct, although at the moment no one pays much attention to this rule. I like turtles, dogs, horses, dolphins and cats. -This is the correct way to write it.