Q. Is it correct or incorrect to put a comma before the “and” in the following sentence: “The Department of Justice has taken on the role of coordinating agencies’ activities, and has undertaken several new initiatives related to dealing with criminals.” I think it’s correct because the second clause—although not an independent clause, strictly speaking—is so long (and the subject is implied). The comma seems to help the reader get through the sentence. Many thanks.

Q. Is the following the correct way to punctuate the date?

Period between June 23, 2003 and March 19, 2004

Q. When I encounter a restrictive clause with multiple elements, do I put a comma at the end of the last element? For example: The woman who was blonde, green-eyed, and slim said hello to me. Or is it: The woman who was blonde, green-eyed, and slim, said hello to me.

Q. Do you perceive any difference in meaning in the following two sentences? (1) Communication patterns must be created so that parallel transmissions are possible when using the RS formula or the DL method, as shown in figure 1. (2) Communication patterns must be created so that parallel transmissions are possible when using the RS method or the DL method as shown in figure 1.

Q. Please, please end a debate I recently had with my European friend over a comma issue as follows: “The Catalan archaeologist, Pere de Palol, started the excavations again.” I feel that it is necessary to delete the commas before and after the name. With them, wouldn’t the sentence imply that there is only one Catalan archaeologist? The text is going to appear on a plaque in a museum.

Q. HELP! I’m arguing with a contract lawyer over this sentence: “The vendor may use the board’s logo on its website and on documents, provided, that such use . . .” I think that the comma after “provided” is wrong, and separates two parts of a single clause. He insists that “with the use of a ‘proviso,’ the second comma is appropriate and correct punctuation.” There are many “provided that” phrases in the document in question, and he wants each of them to be “provided, that.” Am I (a) wrong to think that this comma is incorrect in English? (b) Wrong to think that legal documents are written in English? (c) Not wrong?

Q. When I began learning English grammar from the nuns in or about 1951, I was taught to NEVER use a comma either after or before independent clauses or compound sentences. Did the rules of English grammar and punctuation change while I was in that three-week coma in 1965 or in the years that it took to regain my basic and intellectual functioning before I returned to teaching?

Q. When do you use a comma before “because”? I feel that I never need to put a comma before “because” because any information after it is necessary. What are your thoughts?

Q. I am having a dispute with a local store regarding their return policy, worded as such: “[Retailers] will refund the purchase price of any previewed, defective or mislabeled products returned within 30 days, provided you have the original receipt.” The retailers claim that since the serial comma is not employed, “previewed” becomes a stipulation of both “defective” and “mislabeled.” Under their interpretation of the policy this is equivalent to saying “any previewed defective or previewed mislabeled products.” This is especially important to me, since I purchased a new, defective product from them.

Q. Is there a rule that I’ve missed somewhere that says there should always be a comma before the word “then” if “then” is at the end of a sentence? For example: It’s settled, then. Sometimes it sounds fine; other times it seems more like an obstacle to the flow of the sentence. But a rule is a rule, so if you can point me to the correct section in CMOS, I’ll stop turning up my nose at this construction.