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Difference between by accident or on accident

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In this article, we will explore the nuances of the phrases “by accident” and “on accident”, which are often used interchangeably in English but carry subtle differences in usage and acceptability within various dialects of the language.

Grammar Facts about By Accident and On Accident

Both “by accident” and “on accident” are adverbial phrases used to indicate that something happens unintentionally, without the person involved planning or causing it to happen on purpose. The main grammatical difference between them lies in their prevalence in different dialects of English. “By accident” is the older, more traditional form, widely accepted and used in both British and American English. “On accident”, on the other hand, is a newer variant that has emerged primarily in American English, particularly among younger speakers.

Quick Facts Table

AspectBy AccidentOn Accident
Frequency of UseMore common globallyLess common, mainly younger Americans
AcceptabilityWidely accepted in formal writingConsidered informal and less accepted in formal contexts
OriginOlder, traditional formNewer, emerged in late 20th century
Regional PreferencePreferred in British EnglishMore common in American English

Difference Between By Accident or On Accident

Definition of By Accident

"By accident" means something happened unintentionally, without deliberate planning or cause. It implies a lack of intent behind the action that led to an unintended outcome.

Definition of On Accident

"On accident", while conveying a similar meaning of unintended action, is often perceived as less formal and is primarily used in colloquial American English.

Origin of By Accident

The phrase “by accident” has been in use for centuries, with documented instances dating back to at least the 1600s. Its construction follows a pattern in English where “by” introduces the manner or means by which something happens.

Origin of On Accident

“On accident” appears to have emerged in the 20th century, with its usage increasing among speakers born in the 1990s and later. It may have developed as an analog to phrases like “on purpose,” which contrasts directly with the concept of intentionality.


Both phrases are pronounced as they are spelled, with the emphasis typically placed on the first word of each phrase: “BY accident” and “ON accident”.

Comparing By Accident and On Accident

When comparing “by accident” and “on accident”, the primary distinction lies not in their meaning but in their acceptability and usage across different forms of English. “By accident” is universally recognized and preferred in formal writing and speech, while “on accident” is seen as a regionalism specific to certain American English speakers.

Comparison Table

FeatureBy AccidentOn Accident
FormalityFormal and accepted globallyInformal, primarily in spoken language
UsageUsed in both spoken and written EnglishMostly used in spoken English
PerceptionPerceived as correctOften perceived as incorrect or less educated in formal contexts
Age of PhraseHistorical usageModern, emergent usage

Usage in Sentences with Explanations

Use of By Accident in Sentences

  1. “I found the old photo album by accident while cleaning the attic.” – This sentence illustrates a discovery made without intention during an unrelated activity.
  2. “He deleted the file by accident, not realizing its importance.” – Highlights an unintentional action that led to an unwanted outcome.
  3. “The meeting started early by accident, confusing some attendees.” – An unplanned change occurred without deliberate intention.
  4. “By accident, she stumbled upon a solution to the problem.” – Indicates a fortuitous discovery made without purposeful search or intent.
  5. “The paint spilled by accident, creating a mess on the floor.” – Describes an unintended incident resulting in disorder.

Use of On Accident in Sentences

  1. “I called you on accident; I meant to dial a different number.” – Demonstrates an unintentional action due to a mistake.
  2. “He brought her coffee on accident, not knowing she preferred tea.” – A misunderstanding led to an unintended act of kindness.
  3. “The kids broke the vase on accident while playing indoors.” – An unintended consequence of their actions, emphasizing the lack of intent to cause damage.
  4. “On accident, I booked the tickets for the wrong date.” – Showcases a mistake made without the intention to do so.
  5. “She apologized for stepping on his foot on accident during the dance.” – An accidental action occurring in a specific context, highlighting the unintentional nature of the incident.


Both “by accident” and “on accident” convey the idea of something happening without deliberate intention, but their usage and acceptance vary. “By accident” is the more traditionally accepted form in both written and spoken English globally, while “on accident” has found a niche primarily among younger speakers of American English. Understanding the context and audience is key to deciding which phrase to use.

Commonly Asked Questions

  • Which is grammatically correct, “by accident” or “on accident”?
    • “By accident” is considered grammatically correct and widely accepted across different forms of English, while “on accident” is seen as a colloquial variant that some may not accept in formal contexts.
  • Is “on accident” acceptable to use in writing?
    • It depends on the audience and the formality of the writing. “On accident” is generally acceptable in informal writing but might be avoided in formal or academic contexts.
  • Why do some people say “on accident” instead of “by accident”?
    • The use of “on accident” is influenced by regional dialects and language evolution, particularly among younger speakers of American English. It likely developed as a counterpart to “on purpose.”
  • Can “by accident” and “on accident” be used interchangeably?
    • While they can be used interchangeably in terms of meaning, the choice between them should consider the audience’s expectations and the context’s formality.
Jessica Smith

Jessica Smith

Jessica Smith, writer at, blends creativity with insight, exploring technology, culture, and psychology. With a background in English Literature, she crafts engaging stories inspired by nature and urban life. Outside writing, she enjoys exploring and continuous learning.View Author posts

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