A Word, Please: Questions about grammar? Let the dictionary be your guide

A dictionary on top of a stack of newspapers.
A dictionary can settle varied questions about English usage, writes grammar expert June Casagrande.
(Kirk McCoy / Los Angeles Times)

In the late 1990s, a friend told me she had used the word “exponentially” in a debate with her brother-in-law.

“That’s not a word!” her brother-in-law insisted.

“Of course it is,” my friend replied.

“No, it’s not! And I’ll prove it!”

The brother-in-law then stormed out of the house and into the frontyard of the next-door neighbor, who was working on his lawn, and demanded, “Is ‘exponentially’ a word?”

This would have been perfectly reasonable if it happened in the early 1800s and the neighbor’s mailbox said “N. Webster.” But near the turn of the millennium, when nearly every house in the country contained a dictionary, this ask-a-random-person fact-check strategy was telling. And the unfortunate reality it revealed is still true in the age of Google: Most people don’t know the value of a dictionary.

Dictionaries have a lot more to offer than just word definitions. They also show you different forms of a word, like the adverb form in this entry from Webster’s New World College Dictionary: “exponential … 2. of or increasing by extraordinary proportions — exponentially, adv.”

Dictionaries also tell you how to form tricky plurals, pronounce a word, use an idiom correctly and whether a noun can be used as a verb. Here are just a few examples of the great stuff you can find in a dictionary.

Pronunciations. Not sure how to say “omicron”? Before the internet age, any dictionary could tell you how to pronounce a word, but you had to know all the little symbols and accent marks and schwas. Today you can go to and just click the little speaker button next to the entry word to hear it spoken aloud. “Omicron,” for example, has two correct pronunciations.

When figuring out where to put commas or whether or not you need them, the rules leave room for personal taste, writes grammar expert June Casagrande.

Plurals. Unsure about the plural of cactus, index, octopus or phoenix? Look up “cactus” and you’ll see “plural: cacti or cactuses.” That means both are acceptable. When you need a tie-breaker, go with the first plural listed in the dictionary because that’s what many editors do (it’s a way to ensure consistency). For “index,” you’ll see “indexes or indices.” Under “octopus,” you’ll see “octopuses or octopi.” But in the “phoenix” entry, you’ll see no plurals at all. That’s because the dictionary lists only irregular plurals, not regular ones like “cats,” “matches” and “ideas.” When there’s no plural after an entry word, the dictionary is telling you that the word has a regular plural, formed by adding S or ES to the singular. That’s how you know the plural of “phoenix” is “phoenixes.”

Capitalization. While editing an article about Australia, I paused at the words “down under.” Is that a nickname that should be capitalized? A quick check of Merriam’s and I had the answer: Yes, Down Under is capitalized when it means Australia.

Idioms. An article I edited recently had the expression “get a leg up against the competition.” I had always heard it’s “leg up on,” not “leg up against.” I searched and found, under “leg up,” that Merriam’s offers an example with “leg up on,” so I know that’s an acceptable phrasing. There were no examples with “leg up against,” which means this wording is either less standard or outright wrong.

Phrasal verbs. If you’ve ever wondered whether you “log on to” the web or “log onto” it, you’ve tangled with phrasal verbs. These multi-word verbs have a different meaning from the verb alone. For example, “throw” has a different meaning than “throw up.” In the dictionary, “log on” has an entry and “log onto” does not. So when you say “log onto,” you’re using “log” in a sense you probably didn’t intend, like to record in a journal or to cut a tree.

Parts of speech. There are people out there who will tell you that “impact” isn’t a verb. It’s a noun. So you can have an impact on something, but you can’t impact it. A quick glance in a dictionary will settle this argument: “impact” is listed as both a noun and a verb.

June Casagrande is the author of “The Joy of Syntax: A Simple Guide to All the Grammar You Know You Should Know.” She can be reached at

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