I am currently learning about commas again. I would like to know if this is correct.
For a while, the situation seems to improve, but shortly after that, Mary decides to finally kill herself.
I chose to do it that way because "For a while" is an adverbial determination, ",but" introduces an independent clause, and "shortly after that" is introducing the independent clause?
I still have the feeling there is something wrong with the 3rd comma....?!
"For a while, the situation seems to improve, but shortly after that, Mary decides to finally kill herself."
This is grammatically correct.
Think of it this way: "but" as a conjunction, particularly in this case, introduces an independent clause; likewise, what comes before "but" is also able to stand on its own.
If you want to, you may do this:
"For a while, the situation seems to improve, but, shortly after that, Mary decides to finally kill herself."
This is also correct. In the second example, I just set aside the detail "shortly after that" because, even though it makes the sentence more specific, it is technically not critical.
