my problem sentence is the following:
After completion, or due to termination, the car picks up the crew members and flies them back to the moon.
I would like to make those commas as I put them above. I just can't figure out the rule for this.
My suggestions is that "after completion" and "due to termination" are adverbial clauses. Adverbial clauses are dependent clauses working as an adverb. "After" or "due to" are the subordinating conjunctions that begin the adverbial clause. An dependent clause, or in this case, an adverbial clause at the beginning of the sentence is seperated by a comma.
However, I need to clarify why there is no subject in the adverbial (i.e., dependent) clause: is it omitted? Also, there is no verb in the adverbial clause. There is a subordinating conjunction and a noun?
The other question is why I need to seperate the two adverbial clauses with commas.
Thank you very much for any answer!