problem with AND

pause for effect or meaning

You've probably got a compound subject and don't need a comma. Like:

Bob and Harry went home.

Bob and Harry and Tom went home.

On the other hand, if you are listing people or things, use the comma.

Bob, Harry, and Tom went home.

It's ambiguous what you mean by xxxx... in your example. If each is a sentence by itself, and the "and" links them, then you use a comma, "Bob, Harry and Tom went to the movies, and they had a good time." (I learned to put a comma after each item in a list--"Bob, Harry, Tom, and George". Later a different pedant said you're not supposed to put one after the one just before the "and"--"Bob, Harry, Tom and George"--do whichever you want).

Usually we omit the last comma thus:

Bob, Harry and Tom went home.

I concur.

I was taught not to omit that last comma, not that it really matters, but it's because of phrases like: 'peanut butter and jam', as in I had tea, toast, and peanut butter and jam (they go together, like ham and eggs). There are 11 rules of commas, for those who care, and that's one of them.

Ah, but tintin was not using a phrase like ham and eggs.

I just looked up the 11 rules, and it states that the "and" takes place of the comma.

You should stop tagging Politics for your English learning posts.

It says "Not Politics" Dopey.

It still hangs in Politics forum.

I would suppose there's a chance it's done to try to prevent various and sundry idiots from making political comments on questions of language comprehension/English/grammar.

Thanks a lot guys . That was a hell lot of information . good lesson.

Thanks for your time.

One other thing to note: if you have two independent clauses (two phrases that could be sentences on their own) in the second structure, your sentence is a run-on. The ", and" construction prevents run-on sentences while allowing you to fully connect your ideas (you could also use a semicolon, though without the and). Example: Goldilocks sat in the first chair, and it was too big.

F U N E M ?
S I F M
F U N E X ?
S I F X
M N X 4 2 PLEASE

The comma before the AND is called the Oxford comma or serial comma. Some people use it, some don't; it's a style issue really.

There are special cases, like the "tea, toast, and peanut butter and jam" case, where the meaning is confused if you use a comma before the last AND.

"I had tea and cake, cheese and crackers[,] and toast and jam"

The comma in brackets is the serial comma.
The other ANDs are not part of the "a, b[,] and c" structure, so they don't have a comma before them (and using one would look totally wrong).
In this case, where there are lots of ANDs in the sentence, the serial comma gives it a rhythm that emphasises the intended meaning, so I would always use it in those cases.

"I had tea, cake[,] and toast"

In this simple case, the serial comma adds a pause before the AND, which doesn't seem to clarify the meaning, so I omit it for brevity, but ultimately it is a style issue.

While reading all these posts, and at the same time making dinner, I really learned alot.

for 2 clauses, we have to use comma before AND.
AND is a kind of Coordinating conjunction.
Example:
I like apples.
I want oranges.
* I like apples, and I want oranges (the two ideas have equal importance)

I like apples.
I like oranges.
* I like apples and oranges. (2 objects but only one idea)

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