I have a query about one of the ways I see commas being used in writing because I can't match it up with any of the rules under "the uses of commas" section from your site.
Here is an example of what I'm meaning (quoting directly from your site):
In the sentence "However, it is possible to omit the spaces, especially with em dashes", why is there a comma after "spaces" and before "especially"?
I know it correct grammar because I see it all the time in writing, but I need an explanation on it.
Here's another example I've picked out from the newspaper:
"If only he hadn’t been such an enthusiastic backer of new European President Jean-Claude Juncker, the new hate figure of much of the British media." Again, can you explain why there is a comma at the end of this sentence. I also can't tell whether the part on the sentence before the comma (in this example) is an independent clause or not?