Flies or Flys: Which Is Correct?
Updated · Which One Is Correct editorial team
Quick answer: When asking if flies or flys is correct, the answer is definitive: flies is the only valid spelling. This word serves as the plural for the insect and acts as the third-person singular present tense of the verb. Flys is simply a misspelling that should be avoided in any formal or casual writing to ensure your text remains error-free and professional.
The Short Answer
Flies is correct as both the plural of fly (the insect) and the verb form (she flies); flys is a misspelling.
People often confuse these words because they sound identical when spoken. The silent 'e' at the end of fly causes the 'y' to change to 'ies' when making it plural, similar to how many becomes manyies in some dialects, though strictly following English grammar rules regarding words ending in y.
Side-by-Side Comparison
| Form | Status | Use it when |
|---|---|---|
| flies | Correct | You have five flies in your kitchen, or she flies to the airport. |
| flys | Incorrect | Never use this form because it is always a typo. |
| plural noun | N/A | Refers to multiple insects buzzing around. |
| verb form | N/A | Used when describing an insect or plane flying. |
Correct Example Sentences
- The mosquitoes and other flies swarmed around the porch light at night.
- She flies to Paris every summer to visit her family.
- Do not let the flies land on your food during lunch.
- He flies the small airplane with great skill and precision.
- There are too many flies in the restaurant and customers are leaving.
- The plane flies high above the clouds without any turbulence.
- Please swat the flies before they bite your arm.
- The bird flies south for the winter season each year.
- We need a fan to keep the flies away from our drinks.
- Does she fly a kite or does she fly an actual plane?
Common Mistakes and Fixes
- I caught three flys in the trap.
- I caught three flies in the trap.
- She flys to London next week.
- She flies to London next week.
- Those flys are buzzing all over the room.
- Those flies are buzzing all over the room.
- The plane flys very fast across the sky.
- The plane flies very fast across the sky.
- Please kill all the flys outside.
- Please kill all the flies outside.
- They flys the plane every morning.
- They fly the plane every morning.
A Quick Test You Can Use
To determine if you should use flies or flys, ask yourself if the word refers to more than one insect or describes an action happening in the present tense for a third person. If the meaning involves multiple bugs or a subject like he, she, or it performing the action of moving through the air, the correct choice is always flies, whereas flys will always result in a spelling error regardless of context.
Related Word Pairs
- Whos vs Whose
- Whos is incorrect; use Whose to show possession.
- To vs Two
- To is a preposition; Two is the number 2.
- Its vs It is
- Its shows possession; It is separates the subject and verb.
- Your vs Youre
- Your indicates ownership; Youre is the contraction for you are.
- Affect vs Effect
- Affect is usually a verb; Effect is usually a noun.
Frequently Asked Questions
Is flys ever correct in English?
No, flys is never correct in standard English. It is always a misspelling of flies. Whether referring to insects or the verb form, the correct spelling ends in ies, not ys, to follow standard grammatical rules.
Why do people spell it flys?
People often spell it flys because they do not know the rule for pluralizing words that end in y. They assume adding an s is sufficient, ignoring the need to change the y to i and add es for the correct plural form.
Does flys look like a real word?
Flys looks like a real word but it is incorrect. It resembles the past tense of fly, which is actually flew, or the present tense fly. The combination of fly and s creates an invalid spelling that no dictionary recognizes as standard English.
Can I use flys in creative writing?
You should never use flys even in creative writing. Using a known misspelling distracts readers and makes the work look unprofessional. Always use flies to maintain clarity and respect for the language standards expected in all types of writing.
