Commas Rules (Part 6) with Afterthoughts-English Punctuation

An afterthought is a word, a phrase or a clause that is loosely added to the end of the sentence. An afterthought occurs when you elaborate on ideas when the main idea is already complete.

Most meetings at work are a waste of time, in my opinion.
‘Most meetings at work are a waste of time’. The main idea is complete. ‘In my opinion’ is loosely added to the sentence. ‘In my opinion’ is an afterthought. We need to use a comma before ‘in my opinion'.

Do not use a comma.
When a sentence ends with an adverb that is essential to the meaning of the sentence, there should be no comma before it.
I could attend the meeting instead.