Time Flies or Time Flys? Which is Correct?

You are writing a letter to someone you haven’t seen in quite some time. You would love to start your letter with an idiom about how long it’s been, but is it “time flies” or “time flys”? Which is correct?

“Time flies” is the correct answer here. When you pair a verb, like “fly” with a singular noun, such as “time,” the verb generally takes the third person singular form. In this case, that would be “flies” and not “flys.”

Whether or not you use “flies” or “flys” in a sentence is not cut and dry. It depends on the form of speech the root word “fly” takes. Keep reading to learn more.

What Is the Difference between “Flies” and “Flys”?

The root word “fly” can be either a verb or a noun in a sentence. If “fly” is used as a noun, the plural form of that noun is “flys.”


  • There were a lot of flys gathering around the trashcan.
  • I had a dream that everybody’s flys on their pants were down.

Notice that “fly” in these two examples are things, not actions.

If “fly” is used as a verb or an action word, the plural form in third person singular is “flies.”


  • The bird flies across the open ocean.
  • Everyone watches as the ball flies across the court and goes into the hoop.

In the above examples, “fly” is performing the action of a singular subject.

What Does “Time Flies” Mean?

When someone says, “time flies,” they usually mean that time is moving faster than they expected it to. Time is a singular noun in this type of sentence, so the verb that follows is in third person singular form, which is actually its plural form.


  • Time flies when you are doing something you are passionate about.
  • They say time flies when you find the one you love.

Notice that the phrase “time flies” is usually followed by the word “when.” This shows that the speaker is usually doing something to make them forget the time.

Final Thoughts

“Time flies” is a phrase that people like to use to show that they are preoccupied with something else. It is usually a phrase that shows how engrossed in a situation you are by showing how you have lost track of time.

In most cases, the cause is good, but not always. Either way, because “fly” in this phrase is a verb, saying “time flys” would be incorrect.