You’re putting the finishing touches on your common app essay and you hit a grammatical roadblock. Should you separate a series of three words with one comma or two? What’s the correct way to hyphenate the words fourteen-year-old? When should you use a colon, and when do you use a semi-colon? These questions are among the most common grammatical questions that my students pose. Here are the answers to your questions:


Style Manuals differ in the use of a serial comma. You cannot go wrong using a serial comma. Therefore, if your sentence reads:

My main areas of interest include biology, organic chemistry, and anatomy.

use a second comma before the word and.

Age-Related Terms

Whether being used as a noun or a verb, age-related terms should be hyphenated. You should write:

As a ten-year-old, I was fascinated with science experiments. (age is used as a noun) AND

I was a ten-year-old class clown when I first discovered my fascination with science. (age is used as an adjective)

Semi-Colons and Colons

Use a semi-colon to separate two parts of a sentence, each of which could stand alone as an independent sentence. For example:

Writing has always come naturally to me; poetry, fables, and novellas are genres in which I excel.

Use a colon when introducing greater specificity to your sentence. For example:

I set out everything I would need to create the dish: olive oil, onions, garlic, fresh thyme, white whine, and raw shrimp.

Please look out for future posts addressing other common grammatical pitfalls.