Time has flown by is the correct expression. Time has flew by is grammatically incorrect in standard English.
The confusion comes from the fact that flew and flown are both forms of the verb fly. They are used in different grammatical situations, however. Knowing which form follows has, have, or had makes the answer much easier.
If you are wondering whether to say “time has flew by” or “time has flown by,” always choose “time has flown by.” The expression describes how quickly time seems to pass, especially when you look back and realize that a period has ended much sooner than expected.
Here’s why:
The Core Rule Explained Simply
The verb fly has three important forms:
- Fly, the base form
- Flew, the simple past form
- Flown, the past participle
The key rule is simple: has, have, and had require the past participle when they are used to form perfect tenses.
That means we say:
- Time has flown by.
- The years have flown by.
- The summer had flown by.
We do not say:
- Time has flew by.
- The years have flew by.
- The summer had flew by.
The difference is grammatical, not a matter of personal preference.
Rule 1: Use “Flew” for Simple Past
Use flew when the action happened in the past and you are using the simple past tense.
For example:
- Time flew by during the vacation.
- The afternoon flew by quickly.
- The years flew by after we moved away.
Notice that there is no has, have, or had directly before flew.
Rule 2: Use “Flown” After Has, Have, or Had
Use flown when you are forming a perfect tense with an auxiliary verb such as has, have, or had.
Examples include:
- Time has flown by.
- The last few months have flown by.
- The entire semester had flown by before we noticed.
The helping verb creates the perfect tense, so the verb following it must be the past participle, which is flown.
Side-by-Side Comparison Table
| Situation | Example | Meaning | Correct Usage |
| Simple present | Time flies by quickly. | Time passes quickly. | Flies |
| Simple past | Time flew by quickly. | Time passed quickly in the past. | Flew |
| Present perfect | Time has flown by quickly. | Time has passed quickly up to now. | Flown |
| Present perfect plural | The years have flown by. | Many years have passed quickly. | Flown |
| Past perfect | The years had flown by. | Years had already passed quickly before another past event. | Flown |
| Incorrect perfect form | Time has flew by. | Intended meaning is clear, but grammar is incorrect. | Not flown |
Deep Dive into Category 1: “Time Has Flown By”
Time has flown by is the standard and grammatically correct construction.
The phrase uses the present perfect tense. The structure is:
Subject + has/have + past participle
In this expression:
- Time = subject
- has = helping verb
- flown = past participle
- by = particle forming the phrasal verb fly by
The phrase means that time has passed surprisingly or quickly.
For example:
Time has flown by since I started this job.
This means that the speaker feels the period since starting the job has passed very quickly.
Another example is:
Time has flown by since we first met.
The speaker is looking back from the present and commenting on the period that has passed.
When Should You Use “Time Has Flown By”?
Use time has flown by when you are talking about a period that began in the past and has relevance to the present.
For example:
It is hard to believe that time has flown by so quickly.
The speaker is reflecting on time that has passed up to the current moment.
You can also use it when discussing birthdays, relationships, school, careers, vacations, family events, or major life milestones.
Examples:
- Time has flown by since our wedding.
- Time has flown by since the children started school.
- I cannot believe how quickly time has flown by.
- The past five years have flown by.
- This year has flown by faster than I expected.
Quick Test
Use this quick test whenever you are unsure.
Ask yourself:
Is “has,” “have,” or “had” directly before the verb?
If yes, use flown, not flew.
For example:
Time has ______ by.
The answer is flown.
The years have ______ by.
The answer is flown.
The decade had ______ by.
The answer is flown.
But:
Time ______ by during college.
There is no helping verb, so use the simple past:
Time flew by during college.
That one-word distinction solves most cases.
Deep Dive into Category 2: “Time Flew By”
Time flew by is also correct, but it serves a different grammatical purpose.
Here, flew is the simple past form of fly.
The basic structure is:
Subject + past-tense verb + particle
For example:
Time flew by during our vacation.
The sentence describes a completed period in the past.
Compare these two sentences:
Time flew by during our vacation.
Time has flown by since our vacation.
The first focuses on a completed past period. The second connects the passing of time to the present.
More Examples of “Flew By”
Consider these examples:
The weekend flew by.
This describes a weekend that is now finished.
The weekend has flown by.
This suggests the weekend has passed quickly, with the speaker viewing it from the present.
The afternoon flew by while we were working.
This describes a completed experience.
The afternoon has flown by.
This sounds like the afternoon has passed quickly and is still relevant to the current moment.
Common Patterns
You will often see flew by with a specific completed past time:
- Yesterday flew by.
- The weekend flew by.
- Our vacation flew by.
- The first semester flew by.
- The final year of college flew by.
You will often see has flown by when the speaker is reflecting from the present:
- This year has flown by.
- The last few months have flown by.
- Time has flown by.
- The past decade has flown by.
The grammatical difference is small, but the tense changes the relationship between the event and the present.
The Meaning Shift, or Nuance
The expressions time flew by and time has flown by have almost the same basic meaning. Both suggest that time passed quickly.
The important difference is tense and perspective.
Time flew by places the passing of time firmly in the past.
Example:
Time flew by when I was in college.
The speaker is discussing a completed period.
Time has flown by uses the present perfect and connects the past with the present.
Example:
Time has flown by since I graduated from college.
The speaker is reflecting on the time that has passed since graduation, with the situation viewed from now.
There can also be a subtle emotional difference.
Time has flown by often sounds reflective. It can communicate surprise, nostalgia, or disbelief about how quickly life seems to be moving.
For example:
Time has flown by, and my daughter is already ten years old.
The sentence does more than describe time. It expresses the speaker’s emotional reaction to a life milestone.
Why the Confusion Persists
The main reason people confuse flew and flown is that English verbs do not always follow one predictable pattern.
Some verbs form the past tense and past participle in the same way.
For example:
- Walk, walked, walked
- Work, worked, worked
- Play, played, played
But fly is irregular:
- Fly
- Flew
- Flown
That makes the verb easier to mix up.
Another problem is that people naturally associate flew with the past. That association is correct, but incomplete.
Flew is the simple past form.
Flown is the past participle.
The word flew may sound natural after has in casual speech because both forms are strongly associated with past events. Standard grammar, however, requires the past participle after has in a perfect construction.
This is why “time has flew by” can sound understandable while still being incorrect.
Formal vs Casual Contexts
In formal English, academic writing, professional communication, editing, and polished website content, use time has flown by.
For example:
It is remarkable how quickly time has flown by since the project began.
This is grammatically correct and appropriate for professional writing.
In casual conversation, you may occasionally hear people say “time has flew by.” Native speakers can understand the intended meaning immediately, but that does not make the construction standard.
Casual speech contains many grammatical shortcuts, regional forms, and nonstandard patterns. When writing for a broad audience, especially online, it is better to use the standard form.
For professional content, the safest choice is:
Time has flown by.
Not:
Time has flew by.
This is particularly important when the phrase appears in an article, business message, social media post, school assignment, or public-facing website.
Case Studies and Pop Culture Examples
The expression time flies is deeply established in everyday English. You may hear variations of it in conversations about childhood, aging, relationships, careers, vacations, and major events.
Consider a person looking at photographs from ten years ago.
They might say:
I cannot believe how much has changed. Time has flown by.
The speaker is standing in the present and reflecting on the years that have passed.
Now imagine someone describing a vacation after it has ended:
Our vacation flew by.
This focuses on the completed vacation.
The same distinction appears in storytelling.
A writer might say:
The summer flew by, and soon it was time to return to school.
The simple past works because the writer is narrating past events.
Another writer reflecting from the present might say:
The summer has flown by, and school starts again next week.
The present perfect works because the speaker connects the past period to the present situation.
This pattern appears throughout ordinary English because speakers constantly move between narrating past events and reflecting on experiences from the present.
Advanced Scenarios and Flowchart
Use this decision flowchart when you need to choose between flew and flown.
Start with the sentence:
Time ______ by.
↓
Is there “has,” “have,” or “had” before the blank?
↓ Yes
Use the past participle.
↓
Choose “flown.”
↓
Time has flown by.
If the answer is No:
↓
Are you describing a completed event in the past?
↓ Yes
Use the simple past.
↓
Choose “flew.”
↓
Time flew by.
If you are still uncertain:
↓
Look for a helping verb.
Has + flown
Have + flown
Had + flown
But:
Flew can stand alone as the past-tense verb.
Three-Second Decision
You can reduce the entire rule to this:
Has/have/had → flown
No helping verb + past event → flew
Examples:
Time has flown by.
The years have flown by.
Time flew by yesterday.
The weekend flew by.
Once this pattern becomes familiar, the choice becomes automatic.
Quick Reference Table
| Expression | Correct? | Why |
| Time has flown by | Yes | “Flown” is the past participle after “has.” |
| Time has flew by | No | “Flew” is simple past, not the required past participle. |
| Time flew by | Yes | “Flew” correctly functions as the simple past. |
| Time flies by | Yes | “Flies” is the third-person singular present form. |
| Time had flown by | Yes | “Flown” follows “had” in the past perfect. |
| The years have flown by | Yes | “Flown” follows “have” in the present perfect. |
Common Mistakes That Lower Quality
Mistake 1: Saying “Time Has Flew By”
This is the most common error in this comparison.
Incorrect: Time has flew by.
Correct: Time has flown by.
The problem is the verb form following has.
Mistake 2: Assuming Every Past Form Works After “Has”
Not every past-tense verb can follow has.
For fly, the simple past is flew, while the past participle is flown.
The perfect tense requires flown.
Mistake 3: Thinking “Flew” and “Flown” Are Interchangeable
They are related forms of the same verb, but they perform different grammatical jobs.
Flew = simple past.
Flown = past participle.
That distinction matters.
Mistake 4: Writing “Have Flew”
The same mistake occurs with have.
Incorrect: The years have flew by.
Correct: The years have flown by.
Mistake 5: Writing “Had Flew”
The past perfect also requires the past participle.
Incorrect: The years had flew by.
Correct: The years had flown by.
Mistake 6: Confusing “Flown” With the Present Form
Flown is not the present-tense form of fly.
We say:
Birds fly.
A bird flies.
The bird flew yesterday.
The bird has flown away.
Each form has its own grammatical role.
Memory Hacks That Actually Work
The easiest way to remember the difference is to memorize the complete verb family:
Fly → Flew → Flown
Then connect each form to a tense:
Fly = present
Flew = simple past
Flown = past participle
Here is another useful trick:
Has flown.
The two words naturally belong together. If you remember has flown, you will be less likely to produce has flew.
You can also use a sentence pair:
Yesterday, time flew by.
Since then, time has flown by.
The first sentence uses flew because it describes a past event. The second uses flown because has creates the present perfect.
Another memory trick is to remember that many irregular verbs have a special third form:
Go → went → gone
See → saw → seen
Write → wrote → written
Fly → flew → flown
If you can recognize the pattern, choosing flown after has, have, or had becomes much easier.
Why Precision Matters: SEO and Authority
Correct grammar matters because readers often judge the reliability of information by the quality of its language.
A small error such as “time has flew by” may not prevent someone from understanding the sentence. However, repeated grammatical mistakes can weaken the impression of authority.
This matters especially for SEO content, educational websites, blogs, professional communications, and reference material. Readers expect language-focused content to demonstrate correct language usage.
If an article explaining grammar uses the wrong grammatical form, readers may question the credibility of the entire page.
Using “time has flown by” correctly shows that you understand the difference between a simple past verb and a past participle.
It also makes your writing clearer and more polished.
For content creators, this is important because strong writing combines useful information with accurate language. Search visibility may bring someone to a page, but clarity, credibility, and usefulness help determine whether that content earns trust.
The best approach is simple: learn the rule once, then apply it consistently.
A Quick Quiz
Fill in each blank with flew or flown.
1. I cannot believe how quickly time has ______ by.
2. The weekend ______ by before we knew it.
3. The past few years have ______ by incredibly quickly.
4. Time ______ by while we were on vacation.
5. It feels like time has ______ by since we graduated.
6. The entire summer ______ by.
7. The months had ______ by before the project was completed.
Quiz Answers
1. flown
The correct sentence is “I cannot believe how quickly time has flown by.” The word has requires the past participle flown.
2. flew
The correct sentence is “The weekend flew by before we knew it.” There is no perfect-tense helping verb before the blank, so the simple past flew is correct.
3. flown
The correct sentence is “The past few years have flown by incredibly quickly.” Because have is present, the following verb must be the past participle flown.
4. flew
The correct sentence is “Time flew by while we were on vacation.” This describes a completed experience in the past, so flew is appropriate.
5. flown
The correct sentence is “It feels like time has flown by since we graduated.” The word has requires flown.
6. flew
The correct sentence is “The entire summer flew by.” The sentence describes the completed summer as a past period, so the simple past flew works.
7. flown
The correct sentence is “The months had flown by before the project was completed.” The word had forms the past perfect and therefore requires the past participle flown.
The final rule is easy to remember: “Time has flown by” is correct, while “time has flew by” is not. Use flew as the simple past form when no perfect-tense helping verb is required, and use flown after has, have, or had. Once you remember fly, flew, flown, this common grammar question becomes straightforward. Whether you are writing a school assignment, a professional article, a social media post, or an everyday message, “time has flown by” is the polished standard form.
Conclusion
The correct expression is “time has flown by,” not “time has flew by.” The reason is simple once you understand the three forms of the irregular verb fly: fly, flew, flown. Flew is the simple past form, while flown is the past participle. Because has, have, and had are used with a past participle in perfect tenses, the correct construction is “time has flown by.” For example, you can say, “I cannot believe how quickly time has flown by.” When there is no perfect-tense helping verb and you are describing a completed past event, flew is correct, as in “Time flew by during our vacation.”
The distinction between flew and flown is small but important, especially in professional, academic, educational, and SEO-focused writing. “Time flew by” describes a past situation, while “time has flown by” connects the passing of time with the present. Remember the simple pattern: fly, flew, flown, and pay attention to the helping verb before the blank. If you see has, have, or had, choose flown. If you are using the simple past without those helping verbs, choose flew. With this rule in mind, you can confidently write “time has flown by” and avoid one of the most common mistakes involving this irregular verb.
Frequently Asked Questions
Is “time has flew by” grammatically correct?
No, “time has flew by” is not grammatically correct in standard English. The correct expression is “time has flown by.” The verb fly has three forms: fly for the base form, flew for the simple past, and flown for the past participle. Because has requires the past participle in this construction, flown must be used.
Is “time has flown by” correct?
Yes, “time has flown by” is completely correct. It uses the present perfect tense, with has functioning as the helping verb and flown functioning as the past participle of fly. The expression means that time has passed quickly, usually with the speaker reflecting on how surprisingly fast a period has gone from the past up to the present.
What is the difference between “flew” and “flown”?
Flew is the simple past form of fly, while flown is the past participle. You can say “Time flew by yesterday” because the sentence uses the simple past. You say “Time has flown by” because has requires the past participle. Remembering fly, flew, flown makes the distinction much easier.
Can I say “time flew by”?
Yes, “time flew by” is grammatically correct. It uses flew, the simple past form of fly. For example, you might say, “Time flew by during our vacation.” This describes a completed experience in the past. It differs from “time has flown by,” which uses the present perfect and connects the experience to the present.
Should I use “time has flown by” in formal writing?
Yes. “Time has flown by” is appropriate for formal, professional, academic, and polished writing. It is the standard grammatical construction and clearly communicates that a period of time has passed quickly. If you are writing an article, school assignment, business message, or professional communication, “time has flown by” is the safest and most polished choice.
Why do people say “time has flew by”?
People may say “time has flew by” because flew is strongly associated with the past form of fly, and the distinction between a simple past verb and a past participle can be confusing. Casual speech also contains many nonstandard grammatical forms. However, being understandable does not make the construction grammatically standard. In careful writing, use “time has flown by.”
Is “time has flown by so quickly” correct?
Yes, “time has flown by so quickly” is correct and natural. The phrase often expresses surprise, nostalgia, or disbelief about how rapidly a period has passed. For example, “Time has flown by so quickly since we moved here.” The construction is especially common when discussing birthdays, relationships, vacations, careers, school years, or other meaningful periods.
Is “the years have flown by” correct?
Yes, “the years have flown by” is correct. Because years is plural, the helping verb have is used, followed by the past participle flown. The sentence means that several years have seemed to pass very quickly. You could also say, “The years flew by,” when describing the years from a simple past perspective.
What is the easiest way to remember “flew” versus “flown”?
Remember the three-part verb pattern: fly, flew, flown. Then connect flew with the simple past and flown with has, have, or had. A useful shortcut is “has flown,” because those words naturally belong together. Whenever you see has, have, or had before the verb, choose flown, not flew.
What is the correct phrase, “time has flew by” or “time has flown by”?
The correct phrase is “time has flown by.” The word has is followed by the past participle flown, not the simple past flew. Therefore, “time has flew by” should be avoided in standard English. If you want the simple past instead, you can say “time flew by.” Both correct forms have similar meanings but use different tenses.
