Writers and editors often struggle over whether to insert or delete a comma. Often the choice depends, not on rules, but on what you are trying to say. For example, tonight on a social medium, I shared a post about my favorite candidate’s use of social media to get his message across. I came up with two lead-in sentences for the post, both of which are grammatically correct, but each of which conveys a different meaning:
- So here I am doing my part.
- So here I am, doing my part.
See the difference? Both are grammatically correct. The comma alters the structure of the sentence, changing its meaning. A thoughtless editor might remove the comma from # 2. That would alter the substance of what the writer was trying to say.