Passersby or Passerbys? The Complete Grammar Guide

English has many words that confuse even fluent speakers, and one of the most common examples is passersby or passerbys. If you’ve ever wondered which form is correct, you’re not alone.

Many people naturally assume that adding -s to the end of a noun makes it plural. While that rule works for most words, English contains several compound nouns that follow different grammar patterns.

In this complete guide, you’ll learn the meaning of passersby, the correct plural form, pronunciation, synonyms, examples, common mistakes, and practical exercises. By the end, you’ll know exactly when to use passerby, passersby, and why passerbys is generally considered incorrect.

What Is the Correct Form: Passersby or Passerbys?

The correct plural form is passersby.

✅ Correct: Passersby

❌ Incorrect: Passerbys

The word passerby is a compound noun made up of:

• Passer = a person who passes
• By = an adverb meaning nearby or past

When forming the plural, English grammar changes the main noun (passer) rather than the adverb (by).

Examples

• Several passersby stopped to watch the parade.
• Curious passersby gathered around the street performer.
• The accident attracted many passersby.

Both American English and British English use passersby as the standard plural form.

Passersby or Passerbys Meaning

Definition

A passerby is a person who happens to be passing a place, event, or situation.

The plural form passersby refers to multiple people who are passing by.

American English Meaning

In the United States, passerby commonly refers to someone walking or moving past a location without being directly involved.

British English Meaning

In the United Kingdom, the meaning is identical. British speakers also use passersby as the accepted plural.

Examples

1. A passerby reported the incident to the police.
2. Several passersby helped the elderly woman cross the road.
3. Curious passersby stopped to take photographs.

Passersby or Passerbys in English

Definition

In English grammar, passerby is classified as a compound noun.

The plural form follows a special rule where the principal noun becomes plural.

Grammar Rule

Singular:

• Passerby

Plural:

• Passersby

Similar examples include:

• Mother-in-law → Mothers-in-law
• Attorney general → Attorneys general
• Runner-up → Runners-up

Examples

1. The passersby watched the street magician.
2. Several passersby offered assistance.
3. Passersby often stop to admire the artwork.

Passersby or Passerbys Plural

Definition

The plural form of passerby is passersby.

Why Not Passerbys?

The word “by” is not the noun in the compound. The noun is “passer,” so it receives the plural ending.

Formula

Passer + by

↓

Passers + by

↓

Passersby

Examples

1. Many passersby witnessed the event.
2. Passersby gathered near the fountain.
3. The musician entertained passersby all afternoon.

Passerby Synonym

Definition

A synonym is a word with a similar meaning.

Common Synonyms for Passerby

• Pedestrian
• Bystander
• Onlooker
• Observer
• Witness
• Spectator
• Walker
• Viewer
• Wayfarer
• Traveler

Examples

1. The bystander called emergency services.
2. An observer noticed the unusual behavior.
3. Several pedestrians crossed the busy street.

Passerby Singular

Definition

Passerby is the singular form referring to one person.

Usage

Use passerby when speaking about a single individual.

Examples

1. A passerby found the lost wallet.
2. One passerby stopped to help.
3. The passerby asked for directions.

Singular vs Plural

Singular	Plural
Passerby	Passersby
One person	Multiple people

Passersby in a Sentence

Definition

Using passersby correctly in sentences helps reinforce the grammar rule.

Examples

1. Passersby applauded the talented musician.
2. Several passersby stopped to watch the fireworks.
3. Passersby filled the city square during the festival.
4. Curious passersby gathered around the news crew.
5. Friendly passersby offered directions to tourists.
6. The street artist attracted many passersby.
7. Passersby enjoyed the outdoor performance.
8. Local passersby shared information with authorities.
9. Passersby photographed the historic building.
10. The charity volunteers greeted passersby warmly.

Passersby or Passerbys Examples

Correct Examples

✅ Many passersby witnessed the ceremony.

✅ Several passersby helped clean the park.

✅ Passersby stopped to read the public announcement.

Incorrect Examples

❌ Many passerbys witnessed the ceremony.

❌ Several passerbys helped clean the park.

❌ Passerbys stopped to read the announcement.

Examples Comparison

Correct	Incorrect
Passersby	Passerbys
Many passersby	Many passerbys
Several passersby	Several passerbys

Passersby Pronunciation

Definition

The word passersby is pronounced as:

American English

PASS-erz-bye

British English

PASS-uhz-bye

The differences are minor and mostly related to accent.

Examples

1. The teacher asked students to pronounce passersby correctly.
2. Many learners mispronounce passersby initially.
3. Listening practice improves pronunciation skills.

Other Ways to Say Passersby

Here are alternative expressions you can use depending on context:

• Pedestrians
• Bystanders
• Onlookers
• Observers
• Witnesses
• Spectators
• Walkers
• Travelers
• Visitors
• Strangers
• Crowd members
• Street walkers
• Viewers
• People nearby
• Members of the public
• Local residents
• Commuters
• Tourists
• Sightseers
• Individuals passing by

Common Mistakes to Avoid

Mistake 1

Using “passerbys”

❌ Incorrect

Mistake 2

Adding an apostrophe

❌ Passer’s by

Mistake 3

Using the plural for one person

❌ A passersby

Mistake 4

Using singular for multiple people

❌ Several passerby

Correct Usage

• One passerby
• Two passersby
• Many passersby

Quick Grammar Tip

When a compound noun contains a main noun and another word, pluralize the main noun.

Examples:

• Passerby → Passersby
• Brother-in-law → Brothers-in-law
• Attorney general → Attorneys general
• Mother-in-law → Mothers-in-law

Remember:

The plural goes on the main noun, not the final word.

Fill in the Blanks Exercise

Complete the sentences with passerby or passersby.

1. A __________ found the missing dog.
2. Several __________ stopped to help.
3. One __________ witnessed the accident.
4. Curious __________ gathered around the performer.
5. A kind __________ offered directions.
6. Many __________ attended the street event.
7. The __________ reported the fire.
8. Local __________ enjoyed the festival.
9. One __________ picked up the lost phone.
10. Several __________ took photographs.

Answers

1. passerby
2. passersby
3. passerby
4. passersby
5. passerby
6. passersby
7. passerby
8. passersby
9. passerby
10. passersby

Tips and Tricks

1. One person = passerby
2. More than one person = passersby
3. Never write passerbys
4. The noun is “passer”
5. The word “by” remains unchanged
6. Remember similar forms like mothers-in-law
7. Check whether the subject is singular or plural
8. Read the sentence aloud
9. Use passersby in formal writing
10. Practice with real examples

Conclusion

The confusion between passersby and passerbys comes from the unusual way compound nouns form plurals in English. The correct singular form is passerby, while the correct plural form is passersby. Both American and British English follow the same rule because the noun “passer” is the element that becomes plural, not the word “by.” Understanding this pattern helps you avoid a common grammar mistake and improves your overall English accuracy. Whenever you refer to multiple people passing a location, remember to use passersby. With practice, this grammar rule quickly becomes second nature.

Frequently Asked Questions

Which is correct, passersby or passerbys?

The correct word is passersby, not passerbys. English forms the plural by changing the main noun “passer” to “passers” while keeping “by” unchanged, making passersby the standard and grammatically correct form.

What is the plural form of passerby?

The plural form of passerby is passersby. Since passerby is a compound noun, English grammar adds the plural ending to the noun portion rather than to the final word.

What is the meaning of passersby?

Passersby refers to people who happen to be walking or moving past a particular place, event, or situation. The term commonly describes individuals who are present by chance rather than direct involvement.

How to use passerby?

Use passerby when referring to one person who is passing a location. For example, you can say, “A passerby helped the tourist find the correct street,” to describe a single individual.

Is passerby singular or plural?

Passerby is a singular noun that refers to one person passing by a location. When talking about multiple people, you should use the plural form passersby instead.

Why is passersby the correct plural form?

Passersby follows the grammar rule for compound nouns where the main noun becomes plural. Because “passer” is the noun and “by” functions as an adverb, the plural form becomes passersby.

Can I use passerbys in formal writing?

You should avoid using passerbys in formal writing because dictionaries and grammar guides recognize passersby as the correct plural form. Using the standard form helps maintain accuracy and professionalism.

What is a synonym for passerby?

Common synonyms for passerby include pedestrian, bystander, onlooker, observer, and witness. The best synonym depends on the context and the role of the person being described.

How do you use passersby in a sentence?

You can use passersby to describe several people moving past a place or event. For example, “Curious passersby stopped to watch the street performer entertain the crowd.”

Is passersby used in both American and British English?

Yes, passersby is the accepted plural form in both American and British English. Speakers and writers in both regions follow the same grammatical rule when using this compound noun.