I believe education organizations (e.g., schools, districts, state departments of education) have an obligation to model correct English. Among other responsibilities, they are charged with helping children become successful, contributing members of society, and this means teaching children to communicate well. For this to happen, educators, at all levels, need to demonstrate the highest standard of language use. Children not only learn what they are formally taught but also learn what they observe.
With this in mind, I found the following misuse of commas on a school district website.
Once logged in, highlight the Grades menu, and choose Grades to view your student’s current grades. (http://www.acalanes.k12.ca.us/auhsd/cwp/view.asp?A=3&Q=276874)
This has two commas. The first one is correct, but the second one isn’t.
First Comma: CORRECT
The first comma follows the introductory phrase Once logged in. This comma demonstrates Zen Comma Rule G: Put a comma after introductory clauses and phrases. This phrase is before the subject (i.e., introductory) and describes the main action in the predicate. The comma tells the reader when the introductory phrase ends and when the main sentence is about to begin.
Second Comma: INCORRECT
Now look at the second comma. To understand why it’s wrong, we need to parse this sentence. The subject here is You, which is implied by the imperative (i.e., a command) nature of the sentence. Zen Comma Rule E tells us to use commas as if implied words were present. In this case, we need to add the subject to the sentence to figure out where the commas go or shouldn’t go.
When we put the subject in the sentence, we get this:
Once logged in, you highlight the Grades menu, and choose Grades to view your student’s current grades.
Now that the subject is in place, we see that the sentence has a compound predicate. The sentence has two main verbs and describes two main actions, both of which are linked to the subject You.
Here’s the problem. We don’t separate two parts of a compound sentence with a comma, which this sentence does. To fix this sentence, we need to apply Zen Comma Rule AK: Don’t use commas to separate two parts of a compound predicate. Thus, we remove the second comma.
Need help with commas? Get Zen Comma, a guide to the 17 major uses and misuses of commas. Read more about Zen Comma.