Flys vs Flies: Simple and Clear Guide (2026)

Many students, learners and even native English speakers feel confused when they see flys and flies. Both look very similar. 

Both come from the word fly. But only one is usually correct in normal English writing.

People often ask:

• Is it flys or flies?
• Why does fly change to flies?
• When can we use flys, if ever?

This guide explains everything in very simple English. By the end, you will fully understand the difference and feel confident using the correct form every time.

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Quick Answer

• Flies ✅ is the correct and common form.
• Flys ❌ is usually incorrect and rarely used.

Use flies when:

• Talking about insects
  → The flies are annoying.
• Using the verb fly in present tense (he/she/it)
  → She flies to London every month.

Avoid flys in normal writing.

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Simple Background: Where Do These Words Come From?

The base word is fly.

In English:

• Some words ending in -y change y → i + es
  So:
  • fly → flies
  • cry → cries
  • try → tries

This rule applies when:

• The word ends in consonant + y

Since fly ends in l + y, it follows this rule.

That is why:

fly → flies

This rule makes English spelling easier and more natural.

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Clear Explanation of the Difference

What Does “Flies” Mean?

Flies has two main uses:

1. Plural of the insect “fly”

One insect → fly
More than one → flies

Examples:

• There are many flies in the kitchen.
• These flies are very small.
• Open the window to let the flies out.

2. Present tense of the verb “fly” (he / she / it)

When talking about someone or something that flies, we use flies.

Examples:

• He flies a plane.
• She flies to Dubai every year.
• The bird flies very high.

What Does “Flys” Mean?

In modern English, flys is almost never correct.

Sometimes:

• You may see flys in:
  • Old books
  • Technical writing
  • Special brand or name use

But for normal writing and speaking, do not use flys.

Always choose flies.

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Comparison Table: Flys vs Flies

Feature	Flys	Flies
Common use	❌ No	✅ Yes
Correct spelling	❌ Rare	✅ Correct
Plural of fly (insect)	❌ No	✅ Yes
Verb form (he/she/it)	❌ No	✅ Yes
Used in daily English	❌ Almost never	✅ Always

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Which One Should You Use and When?

Always Use Flies

Use flies when:

• Talking about more than one insect
• Talking about someone or something that flies
• Writing emails, stories, homework, messages, or social posts

Examples:

• The bird flies fast.
• Many flies sit on the food.

Avoid Using Flys

Do not use flys in normal sentences.

Incorrect examples:

• ❌ He flys to school.
• ❌ The flys are everywhere.

Correct versions:

• ✅ He flies to school.
• ✅ The flies are everywhere.

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Common Mistakes People Make

Many learners make simple mistakes with fly → flies.

Here are the most common ones:

Mistake 1: Adding only “s”

• ❌ flys
• ✅ flies

Rule:
If a verb ends in consonant + y, change y → i + es

Mistake 2: Mixing plural and verb forms

• ❌ The bird flys
• ✅ The bird flies

Mistake 3: Forgetting grammar rules

People often write flys because it looks easy. But English spelling rules change y → ies.

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Everyday Real-Life Examples

Emails

• I hope your plane flies safely.
• Many flies entered the room.

News

• The new airline flies to five countries.
• Health officials warn about flies spreading germs.

Social Media

• This bird flies so beautifully.
• Too many flies today 😖

Daily Conversation

• A kite flies high in the sky.
• These flies are annoying.

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Short Learning Section for Students and Beginners

Easy Rule to Remember

If a word ends in:

consonant + y → change y to i + es

Examples:

• fly → flies
• try → tries
• cry → cries
• reply → replies

Simple Trick

Think:

Fly becomes Flies

Say it slowly:

Fly → Flies

Repeat it a few times, and it will stay in your mind.

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Frequently Asked Questions (FAQs)

1. Is “flys” ever correct?

In modern everyday English, no.
Always use flies.

2. Why do we not say “flys”?

Because English spelling rules change y → ies when adding endings.

3. Is “flies” plural or verb?

Both.

• Plural noun: many flies
• Verb form: he flies

4. What is the past tense of fly?

The past tense is flew.

Examples:

• He flew to Canada.
• The bird flew away.

5. What is the continuous form?

Flying

Examples:

• The plane is flying.
• Birds are flying.

6. Is “flys” used in American or British English?

No.
Both American and British English use flies.

7. Can I ever use “flys” in exams?

No.
Always write flies to get full marks.

8. How can I remember this easily?

Remember:

Fly + rule = Flies

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Conclusion

The difference between flys and flies is very easy once you understand the rule.

• Flies is the correct word.
• Flys is almost always wrong.

Whether you are:

• Writing homework
• Sending emails
• Posting on social media
• Learning English as a beginner

Always choose:

FLIES ✅

Now you can use this word with confidence and without confusion.

Keep learning, keep practicing, and your English will become stronger every day 😊