How would this sentence be written? Would a comma go before "and then" or no?
Without comma:
"Brian stole my phone while I was golfing and then Jacob hit him in the face."
With comma:
"Brian stole my phone while I was golfing, and then Jacob hit him in the face."
Best Answer
I follow Chicago Manual of Style for grammar. I would write: "Brian stole my phone while I was golfing, and then Jacob hit him in the face." In this example, 'and' is a coordinating conjunction between two complete clauses, so you would use the comma irrespective of 'then.'
When people say "it's up to the author," I think what they mean is that it's up to the author to assess the meaning of the whole sentence and determine the punctuation according to very real guidelines.
Also, using 'and then' does suggest a correlation - but specifically timing. Did Jacob hit Brian because he stole the phone? Or did he hit him for some other reason, but it just happened to be right after he stole the phone?
One thing I'm trying to do when I write 'and then' is work out if I really need 'then'. Often 'and' suffices, and I'm just writing 'then' out of habit. Another option to describe a true causal relationship would be: "Brian stole my phone while I was golfing, so Jacob hit him in the face." The comma would be needed for clarity, and you've got a tighter sentence. But it totally depends on the context - if you want that causal relationship or timing relationship.