Words to Edit By
One of the main ways we use punctuation is to separate groups of words. Use commas, or sometimes other kinds of punctuation, to set apart words that don’t change the basic thought you’re getting across.
A Realist Take
A word or group of words (A) that makes a critical difference to the meaning of another word or group of words (B) is essential. If it’s a helpful add-on to add interest or extra info, it’s nonessential. If a sentence were a house, the essential clauses1 and phrases2 would be structurally or practically necessary parts of the house.
The other, nonessential stuff isn’t unimportant, but it’s fundamentally decorative. It’s elaboration on the essential stuff. If it were unimportant, you’d probably leave it out completely. That said, if you were to leave out the nonessential (groups of) words in a sentence, the gist of the sentence would remain the same.
If you use commas, parentheses, or em dashes to separate groups of words unnecessarily,3 it might interrupt the flow of the sentence a bit (how rude!) or read a bit funny.
On the other hand, if you don’t use commas (or other appropriate punctuation) to distinguish the nonessential stuff from the essential, you’re playing with editorial fire. Your sentence may technically mean something very different from what you intend. Maybe the misreading is so ridiculous that it won’t trip up most readers—but why take the chance?
Article: Grammar 2.0 — Complete thoughts vs. phrases vs. fragments
For Instance
The sea-folk warrior who had drawn the short straw was expected to carry the banner into battle.
In the sentence above, the clause who had drawn the short straw is essential because there’s no punctuation to set it apart. The implication is that there are many sea-folk warriors, so it’s essential to specify the one who drew the short straw.
The sea-folk warrior, who had drawn the short straw, was expected to carry the banner into battle.
In the sentence above, the clause who had drawn the short straw is nonessential because of the commas setting it apart. The implication is that there’s only possible sea-folk warrior the sentence could be referring to, so the fact that he or she drew the short straw is simply extra info or a helpful reminder to the reader.
Related Editing Guidelines & Tips
[Specific guideline and tip articles will be listed here as they’re published.]
Godspeed and happy rewriting!
Article: Punctuation for clarity
(Art ©2016 by Clonefront. Duly licensed by Vaporous Realms Publishing LLC.)
A clause, grammatically speaking, is a group of words with both a subject and a verb, which may or may comprise a complete thought. For further information, ask Tim Allen.
A phrase is a group of related words that’s a few cookies short of a clause. Maybe it’s a subject without a verb or a verb without a subject. Maybe it’s just clinging to (err, modifying) a subject or a verb like a little word leech.
Unnecessarily is an operative word here. There are legitimate uses, like placing commas between words in a series (list).