Time Flies or Time Flys? Which Is Correct?
Time flies is the correct expression. Time flys is incorrect because flies is the proper third-person singular form of the verb fly. People often use the phrase time flies to say that time seems to pass very quickly, especially when they are enjoying themselves or staying busy.
For example:
- ✅ Time flies when you’re having fun.
- ✅ Time flies during the holidays.
- ❌ Time flys when you’re busy.
If you’re wondering which version to write, always choose time flies.
What Does “Time Flies” Mean?
The expression time flies means that time seems to pass faster than expected.
It is an idiom used in both spoken and written English.
Examples:
- Time flies during summer vacation.
- Time flies when you spend time with friends.
- Time flies once you become a parent.
- Time flies while working on an interesting project.
The phrase does not mean that time literally has wings. It is a figurative expression.
Why Is “Time Flies” Correct?
The word time is a singular noun.
When a singular subject is used in the present simple tense, the verb usually takes -s or -es.
Formula
| Subject | Verb | Example |
|---|---|---|
| Singular | fly → flies | Time flies. |
| Plural | fly | Birds fly. |
Because time is singular:
- Time flies. ✅
- Time flys. ❌
Why Is “Time Flys” Wrong?
Many learners think adding -s makes every verb correct.
However, English spelling rules say that verbs ending in -y often change before adding -es.
Since fly ends with:
- consonant + y
the y changes to i, and -es is added.
fly → flies
Not:
fly → flys
The spelling flys is considered incorrect for the verb.
Grammar Rule: Verbs Ending in Consonant + Y
When a verb ends in a consonant followed by y, change y to i and add -es.
Examples
| Base Verb | Correct Form |
|---|---|
| fly | flies |
| cry | cries |
| try | tries |
| carry | carries |
| reply | replies |
When Does the Rule Not Apply?
If the verb ends in a vowel + y, simply add -s.
Examples:
| Base Verb | Correct Form |
|---|---|
| play | plays |
| enjoy | enjoys |
| stay | stays |
| obey | obeys |
Notice that fly ends with l + y, so it follows the first rule.
What Part of Speech Is “Flies”?
In the sentence:
Time flies.
- Time = noun (subject)
- flies = verb
In another sentence:
The flies are annoying.
Here, flies is a plural noun meaning insects.
Context tells you which meaning is intended.
When Do People Use “Time Flies”?
The phrase is common in everyday English.
Daily Conversation
- Time flies when you’re laughing with friends.
School
- Time flies during the last week of school.
Office
- Time flies when the team is busy.
- Time flies! It has already been a year since our last meeting.
Social Media
- Can’t believe it’s Friday already. Time flies!
Formal Writing
- Time flies as organizations continue to adapt to new technology.
“Time Flies” as an Idiom
The full expression is often written as:
Time flies when you’re having fun.
It means enjoyable moments seem shorter because people pay less attention to the passing of time.
Other variations include:
- Time flies when you’re busy.
- Time flies with good company.
- Time flies before you know it.
- Doesn’t time fly?
Time Flies vs Time Flys
| Time Flies | Time Flys |
|---|---|
| ✅ Correct | ❌ Incorrect |
| Uses the correct verb form | Misspells the verb |
| Standard English | Not accepted in standard English |
| Used in writing and speech | Should be avoided |
Always write time flies.
Common Mistakes
Mistake 1
❌ Time flys when you’re happy.
✅ Time flies when you’re happy.
Why?
The verb fly changes to flies after a singular subject.
Mistake 2
❌ Time fly very quickly.
✅ Time flies very quickly.
Why?
The singular subject time needs the singular verb flies.
Mistake 3
❌ Time are flying.
✅ Time is flying.
Why?
Time is singular, so use is, not are.
Mistake 4
❌ Time flys so fast these days.
✅ Time flies so fast these days.
Why?
The spelling flys is incorrect.
Similar Grammar Patterns
Many verbs follow the same spelling rule.
| Base Verb | Correct Form |
|---|---|
| fly | flies |
| cry | cries |
| worry | worries |
| study | studies |
| deny | denies |
| hurry | hurries |
Learning one rule helps you spell many verbs correctly.
Real-Life Examples
Conversation
A: Has it really been ten years?
B: I know! Time flies.
Classroom
The teacher said,
“Time flies during exam week.”
Workplace
Everyone agreed that time flies when working on an exciting project.
Family
My grandparents always say that time flies as children grow older.
Social Media
“Already August? Time flies!”
Quick Tips to Remember
- Time flies is always correct.
- Never write time flys.
- Remember the spelling rule:
- consonant + y → change y to i + es
- Think of:
- cry → cries
- try → tries
- fly → flies
Practice Exercises
Fill in the Blanks
Choose the correct word.
- Time ______ when you’re busy.
- The bird ______ across the lake.
- She ______ to answer every email.
- He ______ to finish his homework early.
Answers
- flies
- flies
- tries
- tries
Explanation: Each sentence has a singular subject, so the verb takes the correct -ies form where required.
Multiple Choice
1. Which sentence is correct?
A. Time flys quickly.
B. Time flies quickly.
C. Time fly quickly.
Answer: B
2. Which verb follows the same spelling rule?
A. Play
B. Enjoy
C. Cry
D. Stay
Answer: C
Correct the Mistakes
- Time flys when we travel.
Answer:
Time flies when we travel.
- Time fly too quickly.
Answer:
Time flies too quickly.
Rewrite the Sentence
Rewrite using correct grammar.
Time flys when you are learning new skills.
Correct Version:
Time flies when you are learning new skills.
Read Also: Principal vs Principle
Frequently Asked Questions
Is “time flies” grammatically correct?
Yes. It is the correct present simple form because time is singular.
Is “time flys” ever correct?
No. The verb should always be spelled flies.
Why does “fly” become “flies”?
Because verbs ending in a consonant followed by y change y to i before adding -es.
Is “time flies” an idiom?
Yes. It is a common English idiom meaning time seems to pass quickly.
Can I use “time flies” in formal writing?
Yes. It is acceptable in formal and informal English when used appropriately.
What is the full expression?
The most common version is:
Time flies when you’re having fun.
Are there other verbs that follow this rule?
Yes. Examples include tries, cries, studies, worries, carries, and replies
Conclusion
Time flies is the only correct spelling. The mistake time flys happens because many writers forget the spelling rule for verbs ending in a consonant followed by y. When the subject is singular, fly becomes flies, making Time flies the correct choice every time.
Remember this simple pattern: fly → flies, just as cry → cries and try → tries. Once you know the rule, you’ll avoid this common mistake and write with greater confidence.
