Have you ever looked at the calendar and thought, “How did the months disappear so quickly?” When describing that feeling, many English speakers wonder whether “time has flew by” or “time has flown by” is correct.
The correct expression is “time has flown by.” This is because “flown” is the past participle of “fly,” and it must follow “has” in the present perfect tense. In contrast, “flew” is the simple past form of “fly.” Therefore, “time has flew by” is grammatically incorrect, while “time has flown by” is the correct expression.
This distinction becomes easier to understand when you remember the three principal forms of fly: fly, flew, and flown. For example, “Time flies,” “Time flew by,” and “Time has flown by.” However, each form serves a different grammatical purpose, so understanding these forms will help you choose the correct expression. Therefore, learning how they work makes it easier to avoid common mistakes when writing about time passing.
Let’s make this concrete:
- Correct: Time has flown by.
- Correct: Time flew by.
- Correct: Time flies.
- Incorrect: Time has flew by.
Understanding this pattern will help you use “time has flown by” naturally in conversations, essays, emails, social media posts, and professional writing.
The Core Rule Explained Simply
The central rule is straightforward: after “has,” “have,” or “had,” English generally requires the past participle form of the verb.
The verb “fly” has three important forms:
| Verb Form | Word | Example |
| Base form | fly | Time can fly by. |
| Simple past | flew | Time flew by. |
| Past participle | flown | Time has flown by. |
Therefore:
Time has flown by.
is correct.
But:
Time has flew by.
is incorrect.
Why? Because “has” signals the present perfect tense, and the present perfect uses:
has/have + past participle
Since the past participle of fly is flown, not flew, the correct combination is has flown.
Rule One: “Flew” Is Simple Past
Use “flew” when the action happened in the past, and you are describing it using the simple past tense.
Time flew by during my vacation.
The years flew by after graduation.
Summer flew by quickly.
Here, no form of has, have, or had comes before “flew.”
Rule Two: “Flown” Is the Past Participle
Use “flown” after forms of have, has, or had.
Time has flown by.
The years have flown by.
The semester had flown by before we realized it.
This is the pattern to memorize:
has/have/had + flown
Not:
has/have/had + flew
Side-by-Side Comparison Table
| Situation | Example | Meaning | Correct Usage |
| Present/general | Time flies by. | Time seems to pass quickly. | Correct |
| Simple past | Time flew by. | Time passed quickly in the past. | Correct |
| Present perfect | Time has flown by. | Time has passed quickly up to now. | Correct |
| Present perfect plural | The years have flown by. | Many years have passed quickly. | Correct |
| Past perfect | Time had flown by. | Time had already passed quickly before another past event. | Correct |
| Future | Time will fly by. | Time is expected to pass quickly. | Correct |
| Modal | Time might fly by. | Time may pass quickly. | Correct |
| Incorrect present perfect | Time has flown by. | Incorrect verb form after “has.” | Incorrect |
| Incorrect perfect | Time had flown by. | Incorrect verb form after “had.” | Incorrect |
| Past participle | Time has flown by. | Correct perfect construction. | Correct |
Deep Dive Into Category 1: “Time Has Flown By”
“Time has flown by” is the correct choice when you are using the present perfect tense.
The phrase usually describes a period that started in the past and has continued until now, or an experience whose result is relevant to the present.
For example:
Time has flown by since we moved here.
The speaker is looking back from the present and noticing how quickly the period has passed.
Another example:
Time has flown by since the beginning of the year.
The year began in the past, and the speaker is reflecting on the passage of time up to the present.
When to Use “Time Has Flown By”
Use “time has flown by” when the time period is connected to the present.
Common situations include:
- Looking back on recent months
- Reflecting on a relationship
- Discussing a child’s growth
- Talking about school or college
- Describing a vacation
- Discussing a work project
- Reflecting on a major life event
- Commenting on how quickly a year has passed
For example:
I can’t believe how fast this year has gone
Time has flown by since we started this project.
Time has really flown by this year.
It feels like yesterday, but time has flown by.
The Present Perfect Pattern
The structure is:
Subject + has/have + past participle
For “time”:
Time + has + flown
Therefore:
Time has flown.
And with the phrasal adverb:
Time has flown by.
The word “by” emphasizes the idea of passing.
Why “Flew” Does Not Work Here
Consider these two sentences:
Time flew by.
Time has flown by.
The first uses flew because it is simple past.
The second uses flown because it follows has.
You cannot combine the two forms like this:
Time has flew by. ❌
That would be similar to saying:
She has went home. ❌
The correct version is:
She has gone home. ✅
The same grammatical principle applies:
Time has flown by. ✅
Quick Test
When deciding between flew and flown, look at the word immediately before the verb.
Ask:
Is there “has,” “have,” or “had”?
If yes, use flown.
has flown ✅
have flown ✅
had flown ✅
If there is no auxiliary verb and you are describing a completed past event, flew may be correct.
Time flew by. ✅
Quick Checklist
Before writing the sentence, ask:
- Is the sentence in the present perfect?
- Does it contain has or have?
- Am I talking about a period connected to the present?
- Do I need the past participle?
- Is the past participle of fly flown?
If yes, write:
Time has flown by.
Deep Dive Into Category 2: “Time Flew By”
“Time flew by” is also completely correct, but it belongs to a different grammatical structure.
It uses the simple past tense.
For example:
Time flew by during our vacation.
The vacation is presented as a completed past period. The speaker is describing what happened during that experience.
When to Use “Time Flew By”
Use “time flew by” when you are talking about a completed event or period in the past.
For example:
Time flew by during the concert.
The afternoon flew by while we talked.
My childhood seemed to fly by.
The weekend flew by.
The three-hour meeting flew by.
These examples focus on a past period.
The Simple Past Pattern
The pattern is:
Subject + past-tense verb
With fly:
Time + flew
Therefore:
Time flew by.
No “has,” “have,” or “had” is required.
Compare the Two
Look closely:
Time flew by during my vacation.
The vacation is presented as a completed experience.
Now:
Time has flown by since my vacation began.
The sentence connects the past beginning of the vacation with the present.
This is the key distinction.
The Meaning Shift or Nuance
The difference between “time flew by” and “time has flown by” is mainly grammatical, but tense also creates a subtle difference in perspective.
“Time Flew By”
This looks back at a completed past period.
Time flew by during the holiday.
The holiday is treated as a finished experience.
“Time Has Flown By”
This looks from the past toward the present.
Time has flown by since we met.
The meeting happened in the past, but the speaker is reflecting on the period that has continued until now.
“Time Flies By”
There is another useful form:
Time flies by.
This is the simple present.
It often expresses a general observation or repeated experience.
For example:
Time flies by when you’re having fun.
This is not describing one specific past event. It expresses a general truth or familiar observation.
Three Forms to Remember
Think of the pattern this way:
General:
Time flies by.
Past:
Time flew by.
Past connected to now:
Time has flown by.
Once you understand these three forms, the confusion becomes much easier to solve.
Why the Confusion Persists
The main reason this mistake occurs is that “fly” is an irregular verb.
Regular verbs are often easier.
For example:
walk → walked → walked
The past and past participle are identical.
But:
fly → flew → flown
has three different forms.
That makes it easier to accidentally use “flew” where “flown” is required.
Irregular Verbs Create Similar Problems
English contains many verbs with different past and past participle forms.
For example:
go → went → gone
see → saw → seen
write → wrote → written
take → took → taken
fly → flew → flown
Learners often memorize the simple past form first because it appears frequently in everyday storytelling.
As a result, they may remember “flew” but forget “flown.”
Speech Can Add to the Confusion
In rapid conversation, auxiliary verbs can become less prominent.
A speaker may say:
Time’s flown by.
Here, “time’s” means “time has.”
For someone learning English, the sentence may be difficult to hear clearly.
Written examples help reveal the underlying structure:
Time has flown by.
The Word “Flew” Feels More Familiar
“Flew” is strongly associated with actual flight:
The bird flew away.
The plane flew over the city.
Because “flew” is so common, speakers may automatically choose it when they want to describe time moving quickly.
But grammar determines the correct form.
After has, use flown.
Case Studies and Pop Culture Examples
The expression “time has flown by” is common in personal reflections, anniversary messages, graduation posts, birthday captions, interviews, and nostalgic conversations.
Birthdays and Anniversaries
People frequently say:
Time has flown by. I can’t believe you’re already twenty.
The speaker is comparing a past point in time with the present.
Similarly:
Ten years have flown by since our wedding.
The phrase emphasizes how quickly the period seems to have passed.
School and Graduation
A student might write:
Time has flown by. It feels like yesterday that I started college.
The student is connecting the beginning of college with the present.
A different sentence would be:
The four years flew by.
This could be used when looking back on the completed college period.
Work and Career
An employee might say:
Time has flown by since I joined the company.
This suggests the speaker is still connected to the company.
If they have already left:
The five years I spent there flew by.
The completed period is treated as past.
Travel
Imagine someone returning from a trip:
The week flew by.
The trip is finished.
A traveler who is still on the trip might say:
This week has flown by.
The week is currently unfolding.
Personal Reflections
The phrase often appears when people notice how quickly life changes:
Time has flown by since we first met.
This expression combines nostalgia with a connection to the present.
Advanced Scenarios and Flowchart
Use this decision process when you’re unsure whether to write flew or flown.
Start with your sentence.
→ Time has flown by.
→ Periods have flown by.
→Moment had flown by.
↓ No
Are you describing a completed event in the past?
↓ Yes
Use flew.
→ Time flew by.
→ The weekend flew by.
↓ No
Are you stating a general observation?
↓ Yes
Use flies.
→ Time flies by.
↓
Are you talking about the future?
↓ Yes
Use will fly.
→ Time will fly by.
The shortcut is:
has/have/had → flown
simple past → flew
general present → flies
future → will fly
Quick Reference Table
| Expression | Correct Form | When to Use It |
| Time flies by | Yes | General observation |
| Time flew by | Yes | Completed past event |
| Time has flown by | Yes | Past-to-present connection |
| Time had flown by | Yes | Earlier past event |
| Time will fly by | Yes | Future expectation |
| Time has flown by | No | Wrong past form after “has” |
| Time has flown by | No | “Time” is singular, so use “has” |
| The years has flown by | No | “Years” is plural, so use “have” |
| The years have flown by | Yes | Plural subject with present perfect |
| Time is flown by | Usually no | Incorrect for the intended active meaning |
Common Mistakes That Lower Quality
Mistake 1: “Time Has Flew By”
This is the most common error.
Incorrect: Time has flew by.
Correct: Time has flown by.
Remember:
has + past participle
The past participle is flown.
Mistake 2: “Time Have Flown By”
Because “time” can refer to many moments or years conceptually, learners sometimes treat it as plural.
But in this expression, time is an uncountable singular noun.
Therefore:
Time has flown by.
not:
Time have flown by.
Mistake 3: “The Years Has Flown By”
Now the subject is plural:
The years have flown by.
Use have, not has.
Compare:
Time has flown by.
The years have flown by.
Mistake 4: Using “Flew” After “Had”
The same rule applies to had.
Incorrect: Time had flew by.
Correct: Time had flown by.
The past perfect requires:
had + past participle
Therefore:
had flown
Memory Hacks That Actually Work
Hack 1: Memorize “Flew, Flown”
Say this sequence aloud:
Fly, flew, flown.
Think:
Now → Past → Perfect
This gives you the basic pattern.
Hack 2: Pair “Has” With “Flown”
Create a mental pair:
has flown
Do the same with:
have flown
and:
had flown
Whenever you see one of these auxiliary verbs, your brain should immediately expect flown.
Hack 3: Use a Three-Sentence Pattern
Memorize these three sentences:
Period flies by.
Ocean flew by.
Time has flown by.
These represent three major tense patterns.
Hack 4: Compare With “Go”
Another useful irregular verb is:
go → went → gone
You would say:
She went home.
But:
She has gone home.
Likewise:
Time flew by.
But:
Time has flown by.
This parallel can make the difference easier to remember.
Why Precision Matters, SEO and Authority
Grammar accuracy matters when you are creating educational, professional, or SEO-focused content because readers expect language information to be reliable.
A person searching “time has flew by or time has flown by” is usually looking for a quick, authoritative answer. If the explanation contains additional grammar errors, the reader may lose confidence in the content.
Clear grammar explanations also improve user experience.
A strong answer should quickly establish:
“Time has flown by” is correct.
Then explain why:
“Flown” is the past participle of “fly,” and it follows “has” in the present perfect tense.
That gives readers both the answer and the rule.
Precision Supports Trust
When an article consistently distinguishes:
- flew from flown
- has from have
- simple past from present perfect
- singular from plural subjects
it demonstrates careful attention to language.
That matters for websites that publish grammar guides, educational resources, ESL content, or professional writing advice.
Precision Improves Search Intent Satisfaction
Someone searching this exact phrase probably wants to know:
- Which version is correct?
- Why is it correct?
- What is the difference between “flew” and “flown”?
- When should each form be used?
- Can they use “time flies by” too?
A useful article should answer those questions directly.
Precision Prevents Repeated Errors
Once a learner understands:
has + flown
they can apply the same rule to other irregular verbs.
That makes the lesson more valuable than simply memorizing one sentence.
For example:
She has gone.
He has written.
They have seen.
Time has flown.
The same principle appears throughout English grammar.
A Quick Quiz
Fill in each blank with the correct form.
1. I can’t believe how quickly time ______ by this year.
A. flew
B. has flown
C. fly
2. The weekend ______ by while we were traveling.
A. flew
B. has flown
C. flown
3. Time ______ when you’re having fun.
A. flew
B. flies
C. flown
4. The years ______ by since we graduated.
A. has flown
B. have flown
C. flew has
5. By the time we noticed, the afternoon had ______ by.
A. flew
B. flies
C. flown
6. Which sentence is correct?
A. Time has flew by.
B. Time has flown by.
C. Time have flown by.
7. Which sentence uses the simple past correctly?
A. Time flew by during the vacation.
B. Time has flown by during the vacation.
C. Time flew by during the vacation.
8. Which sentence refers to the future?
A. Time flew by.
B. Time has flown by.
C. Time will fly by.
Answers
1. B, has flown
2. A, flew
3. B, flies
4. B, have flown
5. C, flown
6. B, Time has flown by.
7. A, Time flew by during the vacation.
8. C, Time will fly by.
Conclusion
Choosing between “time has flew by” and “time has flown by” is simple once you remember the three forms of the verb fly: fly, flew, flown. The correct expression is “time has flown by” because “has” requires the past participle, and “flown” is the past participle of “fly.” By contrast, “time flew by” is correct when using the simple past tense, while “time flies by” expresses a general observation.
The most reliable memory trick is to connect has, have, and had with flown. When you see one of these helping verbs, avoid “flew” and choose “flown.” For everyday conversation, professional writing, social media, essays, and grammar-focused content, “time has flown by” is the correct present-perfect expression.
Frequently Asked Questions
Is “time has flew by” correct?
No, “time has flew by” is grammatically incorrect. The correct expression is “time has flown by.” The reason is that “has” requires the past participle in the present perfect tense. The three forms of the verb are fly, flew, flown, so “flown” must follow “has.”
Is “time has flown by” grammatically correct?
Yes, “time has flown by” is completely correct. It uses the present perfect structure has + past participle, with “flown” serving as the past participle of “fly.” The phrase means that time has passed quickly, usually emphasizing a period that began in the past and remains connected to the present.
What is the difference between “time flew by” and “time has flown by”?
“Time flew by” uses the simple past and usually describes a completed period in the past. “Time has flown by” uses the present perfect and connects past time with the present. For example, “The weekend flew by” describes a finished weekend, while “The year has flown by” reflects on the year up to now.
Why is “flown” used after “has”?
“Flown” is the past participle of the irregular verb fly. The present perfect tense follows the pattern has or have + past participle. Therefore, “has flown” is correct. “Flew” is the simple past form and cannot normally be used after “has” in this construction.
Can I say “time flies by”?
Yes, “time flies by” is correct. It uses the simple present tense and usually expresses a general observation or familiar truth. For example, “Time flies by when you’re having fun” means that enjoyable experiences often seem to pass quickly. It is different from the past and present perfect forms.
Is “time flew by” also correct?
Yes, “time flew by” is correct when referring to a completed event or period in the past. For example, “Time flew by during our vacation” describes a past vacation. Because the sentence uses the simple past tense, “flew”, rather than “flown,” is the appropriate verb form.
What is the past participle of “fly”?
The past participle of “fly” is “flown.” The three principal forms are fly, flew, flown. For example, “Birds fly,” “The bird flew away,” and “The bird has flown away.” Remembering these three forms helps you choose the correct verb when using different English tenses.
How can I remember “flew” versus “flown”?
Use this simple rule: flew = simple past, while flown = past participle. If you see has, have, or had, use “flown.” For example, “Time flew by yesterday” is correct, while “Time has flown by this year” is correct. Memorizing fly, flew, flown can make the distinction automatic.
