Ah, okay it's the only one with all of this combined.
Commas as a list. Should have put in the final 'Oxford Comma' as well. That's a heated debate amongst grammarians but there's no benefit to leaving it out and there are instances where its absence is confusing. Hence leave it in!
Still unsure about the correct use of commas.
I ended up creating a simplified grammar in order to teach it effectively. It's actually pretty easy when taught right. Just most folk don't know the rules (including primary/middle school teachers - 'when you take a breath'
) and throw commas around willy-nilly. And then when knowledgeable folk do try to explain them, they go into ordinate and subordinate clauses and all sorts of gobbledegook that people didn't actually think about when they invented the comma. It boils down to (contemporary use):
1) commas as lists
Today I need to get the secondary character spawning in the tute, change the spawn graphics, update the enemy AI, and introduce some combat.
“Her favourite foods are sausages and mash, raspberry jam, fish and chips, jelly and ice cream, and Marmite.”
Notice the benefit of the last comma. Does she like jelly and ice-cream and Marmite all together, or is the Marmite a separate item? With that last comma we know.
2) structuring a sentence so people can parse it more easily
Expression of ideas starts with a
subject followed by what we want to say about it.
Mr. Fox is a peculiar fellow with a peculiar smell who none of us really like though we pretend we do.
For interesting writing/reading, we can rearrange that info to precede the subject with some info about it. However, the reader is then at a loss as to what the hell we're talking about unless we make it clear when the subject arrives on the scene.
A peculiar fellow with a peculiar smell, Mr. Fox is someone who none of us really like though we pretend we do.
3) separating a sentence into high- and low- priority parts
Just like brackets, you use commas around a phrase to shift a piece of info into an aside. The sentence maintains its meaning without that comma'd out fragment.
Mr. Fox is a peculiar fellow, with a peculiar smell, who none of us really like though we pretend we do.
His particular aroma isn't as important as the rest of the info, but the reader may want to know.
Peter took the bus in the morning, on Wednesday with his dad, over the Severn Bridge to his grandmother's mansion.
Reads as,"Peter took the bus in the morning over the Severn Bridge to his grandmother's mansion. Oh, and that was Wednesday, with his dad." Whereas...
Peter took the bus, in the morning on Wednesday, with his dad, over the Severn Bridge, to his grandmother's mansion.
Reads as..."Peter took the bus with his dad to his grandmother's mansion. Oh, and that was Wednesday morning, and they went via the Severn Bridge."
Edit: there's another appearance of the comma, which confuses people when trying to make sense of them, where it's optionally coupled with a connective like 'and' or 'but' to just add a bit of 'space' between the ideas.