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I'm pretty sure this is a duplicate, but it's a generic case and searching brings up thousands of examples, so I'm forced to post.

The question is, which of the sentences below is punctuated correctly?

A. I work at Google a search company.

B. I work at Google, a search company.

And in that vein, as a sub-question, which of these is correct, if I am trying to say that I enjoy each of the three lunch meats individually?

C. I enjoy liverwurst, bologna, and spam.

D. I enjoy liverwurst, bologna and spam.

share|improve this question

closed as general reference by FumbleFingers, jwpat7, simchona, Mitch, Daniel Mar 7 '12 at 14:22

This question is too basic; it can be definitively and permanently answered by a single link to a standard internet reference source designed specifically to find that type of information.If this question can be reworded to fit the rules in the help center, please edit the question.

On question 1, sentence B is correct since the phrase a search company is an appositive and as such must be comma-delimited. On question 2 search on this site for "Oxford comma". On question 3, all your sentences are independent clauses but your questions are not specifically about clauses. – Shoe Feb 21 '12 at 7:15
I would just add that if your intention in the second question is to avoid confusion about your liking all of the "meat", then I would use or instead of and. – Sam Feb 22 '12 at 3:41
up vote 2 down vote accepted

I work at Google[,] the search company.

You need a comma here. The comma functions like parentheses — it shows that you could delete the clause and the sentence would still make sense.

Here’s an example of a sentence with a clause that needs and a clause that doesn’t need commas:

Barack Hussein Obama the Second, the forty-fourth President of the United States, was born in Hawaii.

In this sentence we write “the Second” (usually just “II”) to distinguish him from his father, also called Barack Hussein Obama. We need this to make it clear who we are talking about, so we don’t use a comma. But now that we have established who he is, all the stuff about being the forty-fourth president is just extra information — we could delete it and the sentence would still make sense — so we wrap it in commas.

I enjoy liverwurst, bologna[,] and spam.

There are excellent reasons why you shouldn’t use a comma, and there are excellent reasons why you should. This has led to so much passionate, pointless debate that there’s even a song about it! I suggest you read up on the matter [Wikipedia link]and form your own conclusions — just remember to be consistent.

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That's a really good explanation - perhaps not superlative, but pretty darn good! Thanks! I'd like to hear more about Champion, though. :) – Ben Feb 21 '12 at 8:27
And +1 for the song. No way I'll forget that now. – Ben Feb 21 '12 at 8:36
Sorry, but I deleted Champion the Wonder Horse. I thought of a better example. – Pitarou Feb 21 '12 at 23:10
−1: There are no ‘excellent’ reasons to neglect the Oxford Comma. Although lynching is too strong a sentence, or verb, for the crime, it is still something that will get you righteously ruler-slapped by Sister Indomitable as she assigns you your penance to write a compiler without benefit of lex or yacc. Good luck on those fundamentally unsolvable reduce-reduce errors you’ve insisted on introducing to the parse. Computers don’t like it, and neither do people. Consistency will get you everywhere, and inconsistency will get you FAIL. – tchrist Feb 22 '12 at 0:38
@tchrist I can't believe you downvoted me for saying that the Oxford comma is a matter of debate! You appear to be intent on igniting the abovementioned passionate, pointless debate. I will not rise to it. – Pitarou Feb 22 '12 at 6:50

In the first example the correct solution is with the comma:

I work at Google, the search company.

The reason: The comma in this case denotes a non-defining relative clause. Google is a well-known company, therefore you do not need to define which Google you mean; there's only one! Therefore, if the following works:

I work at Google.

Then you can use a comma to create a non-defining relative clause to comment on the first sentence.

As for the second example - this is a bit different. In lists you usually do not put a comma before and, but this sometimes results in ambiguity, like for example:

These cables are red, yellow, black and white.

This sentence is ambiguous as the last item in the list, "black and white" might be considered as one item; a cable with two colors!

To help disambiguate such cases there's something we call a serial comma. You can put it before "and" preceding the last item in a list, especially for the aforementioned reasons. The result would be:

These cables are red, yellow, black, and white.

share|improve this answer
Thanks RiMMER, +1 for that interesting link - perhaps Google was a bad example, since I meant to be generic. Let's say: I work at FooBarBaz, a search company. Same still holds true? – Ben Feb 21 '12 at 8:21
Also, please note (if necessary) that the original question used a, not the. – Ben Feb 21 '12 at 8:26

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