A comma is a small mark that can make a huge difference. In legal contracts, the presence or absence of a single comma has controlled the loss or gain of millions of dollars. What makes it so powerful? Answer: the control of how we group words, which can change the meaning of a sentence.
Consider this simple example:
(1) “What should I ask for today?”
When you read that sentence, did you understand what was meant? Of course you did. What else could it be? You probably meant one of two possibilities: either you wanted to know what would meet today’s needs or you wanted to know what today’s request should be. How can you be sure your thought will always have the same meaning for readers? For that, the comma plays a crucial role.
(2) “What should I ask, for today?” When we separate the preposition from the verb with a comma, readers should know the question is seeking to satisfy today’s needs.
(3) “What should I ask for, today?” When we use a comma to separate “today” from “ask for,” we’re asking what request should be made now instead of later.
While the comma is helpful, you can’t keep readers from never noticing the comma. After all, they’re reading for information or entertainment, not to sign a legal contract. Therefore, example (3) might be better written like the next example, with “today” placed where it can’t possibly be associated with the preposition.
(4) “Today, what should I ask for?
Instead of watching your p’s and q’s, watch your commas, because they are more important.