Yeah, there's that sense of surprise achievement
The answer is boringly nerdy - at least I think so. I'm often wrong on these things, but thought I'd give it a go anyway. I used two similar examples in the hope of making the second feel like the first, when it's really much more complicated. It all comes from the post we had on use of commas a couple of weeks back. The first sentence is simply a list:
I went into the shop, bought a book and talked to the owner.
but the second is two sentences patched together:
I went into the shop, talked to the owner. I bought a book.
The first comma is a gapping comma, (what we think of as a pause comma) replacing the need to repeat "I". To link the two, we can't just use "and", because it's a compound sentence, so we have to use another comma.
I went into the shop, talked to the owner, and I bought a book.
That's the way I read it, and I could be wrong - but am I right in thinking that in a compound sentence the conjunction
must be preceded by a comma?
Colin M