Something I’ve run into fairly recently is whether or not to put a comma before “too” or “also.” I’d never thought about it much, and I probably just used one when it seemed necessary, but I started noticing that some writers use one every time. Perplexed, I found the answer in an old grammar book.
It’s actually quite simple: If the emphasis in the sentence is on the word or words just before “too,” put a comma. Otherwise, leave it out.
Whether or not there is a comma can actually change the meaning of the sentence. For example:
He likes baseball too.
What does this tell us? He likes baseball as well as someone else. The emphasis is on the word “he.”
Note the difference: He likes baseball, too.
In this sentence the emphasis is on the word “baseball,” indicating that he also likes other sports or activities.
I keep it straight by separating the emphasized word from “too” or “also” when it’s at the end of the sentence. If the emphasized word is near the beginning, I don’t use a comma.
Here’s another example of how the meaning of a statement is changed depending on whether or not a comma is used:
He’s going to town also. (He’s going to town as well as another person.)
He’s going to town, also. (He’s going to town as well as some other place.)
After reading variations of the use of commas before these two words, I’m glad to find an easy way to be consistent and get it right every time.