Flys vs. Flies – Which Spelling is Correct?

/ October 15, 2019/ Usage

What’s the Difference Between Flys and Flies?

Flys and flies are homophones. Both can be plural nouns, and one can also be the third person singular form of the verb fly. However, they have separate definitions which rarely overlap.

Flys is a plural noun. The singular form is fly. However, flys is not the plural form of every meaning of fly. It is only the plural form of fly in the sense of a zipper on the pants in the crotch area, a fly ball in baseball, an antique type of carriage, and the area over a stage.

• The twins have on matching pants, and their flys are down on each of them. (zipper sense)

Flies is the plural form of fly in the sense of the winged insect. It is also the third person singular conjugated form of the verb fly, in the sense of an airplane, bird, or anything moving through the air.

• My grandmother always flies on American Airlines. (verb form)

Let’s look at some of the ways to use each of these words in English.

Using Flys in a Sentence

When to use flys: Flys is almost never used. In fact, usually when this word does appear it is because someone accidentally misspelled flies. However, flys can be correct as the plural form of fly in several unique cases. The first of these is when it refers to the zipper on the front of a pair of pants. This is the most common. It can also be a shorter form of saying fly balls. However, the two-word expression fly balls is more common and therefore better to use. Flys can also refer to the plural form of a type of carriage from the 1800’s. However, most people seldom have cause to mention this, so you will likely never see it, or need to use it, in this way. Finally, it can also mean the plural form of the area over the stage in a theater. This is a technical term that you probably wouldn’t need to know unless working in a theater. Additionally, the plural form of the word in this sense usually appears as fly riggings.

For example,

• The parents must teach their children to zip up their flys. (zipper meaning)
• The lords and ladies all arrived on their flys, drawn by beautiful horses. (carriage meaning)
• Only employees of the theater are allowed to operate the lighting and the flys. (stage meaning)
• The baseball fan has caught many flys over the years. (baseball meaning)

In general, the use of flys is so rare that it is almost always incorrect. Even in the rare cases that it is correct, people may assume it is incorrect due to its rarity. Therefore, it may be better to use synonyms in place of flys, simply to avoid confusion.

Using Flies in a Sentence

When to use flies: Flies can act either as the plural form of the insect, fly, or the third person singular conjugation of the verb fly. Flies is also an accepted alternative spelling for a zipper fly and a baseball fly. The verb fly means to move through the air. It can also sometimes mean to move very quickly.

For example:

• The picnic was ruined by the hundreds of flies that swarmed the food and the people.
• My daughter is always so eager to get to school in the morning that she flies out the door at 7AM on the dot.

Usually flies as an insect refers to house flies. However, several other insects use flies in their names, including dragonflies, butterflies, and fireflies.

Remembering Flys vs. Flies

You can use the spelling of these two words as a mnemonic device to remember which one is which.

One of these ways is to remember that flies has more letters, and likewise it is the more common way to spell the word. It follows the same spelling rule as most other words ending with consonant + y. Other examples include baby/babies, army/armies, body/bodies, puppy/puppies, kitty/kitties, and many more.

You can also remember that a fly system in a theater is pluralized with the y intact, just as system contains a y. Alternatively, you could simply pluralize this as fly systems.

Finally, because a fly carriage is pluralized with the y intact as well, you could also remember that back in the 1800’s, a carriage was key to traveling in style. Key and style both retain the y in their plural forms, just like flys does.

Outside Examples

• Three years ago, she couldn’t do a single push-up and certainly had never heard of a “reverse fly.” Today, Solveig McCulloch, 79, can do 10 push-ups easily and rocks her five-pound dumbbell flys. –Chicago Tribune
• One parent would throw batting practice or hit grounders; the other would shag flys in the outfield or take throws at first. –New York Daily News
• Flies really do spread germs, a new study confirmed. The insects are not only annoying by trying to land on your meal or crawling over kitchen countertops, they also carry more diseases than previously thought. –New York Post
• Mississippi is lauded as the only state to have such a museum, but it was also among the most violent antagonists of the civil rights movement and to this day flies a state flag adorned with a banner of the Confederacy. –New York Times

Quiz: Flys vs. Flies

Instructions: Write the correct word in each blank, either flys or flies.

1. I love everything about summer except for all the annoying ___________ that buzz around.
2. It’s rare to see anyone traveling in horse-drawn _________ these days.
3. The lone eagle ____________ over the land.

See answers below.

Article Summary

Should I use flys or flies? These two words have different definitions which only occasionally overlap. Usually, only one of them is correct.

• Flys is a very rarely used form of the plural of fly. It only appears in the sense of a zipper on pants, a fly ball in baseball, a carriage drawn by horses, and the rigging system in theaters.
• Flies is much more common. It refers to a type of flying insect, as well as a conjugation of the verb fly, meaning to move through the air.

Using the context above can help ensure you always remember to the difference between these two words.

Answers

1. flies
2. flys
3. flies