What is the reason for why this comma use is correct?

Question

I drift off to bed, no longer shivering.

Shouldn't there not be a comma in this sentence since the words after seem to be a dependent clause? How can I explain that this comma is correct?

Answer 1

The comma is correct because you do no have a complex structure. You have a parenthetical phrase, an additional notation.

Answer 2

The phrase "no longer shivering" is not a dependent clause because it does not have both a subject and a verb.

Rather, it is a participle phrase. More information here: https://www.grammarly.com/blog/participial-phrases/

Technically, a comma should not be used when a participle phrase is at the end of the sentence. However, because the phrase is not next to the noun that it is describing ("I"), the sentence would be unclear without the comma. Without the comma, it would imply that the "bed" was no longer shivering.

Note: Many dependent clauses are set off by commas. Example: "While they ate cake, he only had salad."