In One Occasion vs. On One Occasion – Which is Correct?
The correct phrase is “on one occasion,” not “in one occasion.” Use on when referring to a particular event or instance: “I met her on one occasion.” In is appropriate with expressions such as “in one case” or “in one instance,” which may explain the common preposition confusion among learners.
In One Occasion or On One Occasion – Which Is Correct?
On one occasion is the standard phrase in English. It means “once” or “at a particular time.” The phrase in one occasion is generally considered incorrect or nonstandard when you mean a single event.
The confusion happens because English uses in with similar expressions such as in one case, in one instance, and in one situation. However, the conventional preposition before one occasion is on.
The Best Trick to Remember the Difference
Use this simple association: you are on an occasion, just as you are on a special day or on an event date. You can also replace on one occasion with once. If the sentence still makes sense, on one occasion is probably the correct choice.
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| in one occasion | Nonstandard phrase | Not the usual standard-English form for referring to one event | Avoid: “I saw him in one occasion.” |
| on one occasion | Prepositional phrase | Once or at one particular time | “I saw him on one occasion.” |
How to Use On One Occasion
On one occasion refers to a single event or a particular time in the past. It commonly introduces an anecdote, an exception, or an example. The expression is grammatically correct in both American and British English.
The phrase has a moderately formal tone. In casual conversation, once or one time is often more natural. In essays, reports, biographies, and formal narratives, on one occasion is a useful way to describe a specific incident.
Example 1: On one occasion, the manager stayed late to help the new employee.
Example 2: I had lunch with the author on one occasion after a public lecture.
Example 3: On one occasion, the machine stopped working without warning.
Etymology of the Phrase On One Occasion
Occasion comes through Middle English and Old French from the Latin occasio, meaning an opportunity, event, or favorable circumstance. English traditionally uses the preposition on with particular events or instances, as in on that occasion, on this occasion, and on one occasion.
Related Concepts
Understanding prepositions used with events and instances helps explain why on one occasion is correct while in one occasion is not normally used.
- Prepositions of time: English uses different prepositions for different time relationships. For example, we say at noon, on Monday, and in July.
- Fixed phrases: Some combinations are established through long-standing usage. On one occasion, on that occasion, and on this occasion are fixed expressions.
- Synonyms for once: The phrase on one occasion can usually be replaced by once, one time, or at one point, depending on the context.
- Instance versus occasion: In one instance is correct because instance commonly follows in. This pattern should not be transferred to occasion.
Examples from Media and Literature
The following examples demonstrate how on one occasion works in narrative, journalistic, and everyday contexts:
- Literary narration: “On one occasion, the traveler reached the village just before sunset.” This construction helps introduce an isolated event in a story.
- Biography: “On one occasion, the scientist gave an unscheduled lecture to a group of students.” The phrase highlights a memorable incident in someone’s life.
- News writing: “On one occasion, the agency issued a warning before the storm changed direction.” The expression identifies one specific event within a broader report.
- Film or television dialogue: “I met the director on one occasion, but we never worked together.” The phrase sounds slightly more formal than “I met the director once.”
- Personal anecdote: “On one occasion, my neighbors rescued a stray dog during a snowstorm.” This usage introduces a single remembered experience.
On One Occasion Synonyms
| Synonym | Definition |
|---|---|
| Once | At one time or one time only |
| One time | During a single past event |
| At one point | At a particular moment or stage |
| On a single occasion | During one specific event, with emphasis on its singular nature |
| At one time | Previously or during a particular period |
Frequently Asked Questions
Question 1: Is “in one occasion” grammatically correct?
Generally, no. When you mean “once” or “at one particular event,” the standard phrase is on one occasion. Use in one instance or in one case if you want to use the preposition in.
Question 2: What does “on one occasion” mean?
It means “once” or “at a particular time.” For example, “On one occasion, she visited the museum alone” means that she visited it alone one time.
Question 3: Is “on one occasion” formal?
It has a moderately formal or narrative tone. In casual speech, once or one time may sound more natural, while on one occasion works well in professional writing and storytelling.
Question 4: Can I say “on one occasion” in American English?
Yes. On one occasion is standard in American English as well as British English.
Conclusion
Use on one occasion when referring to one specific event or time. Avoid in one occasion in standard English, and use alternatives such as in one instance or in one case when appropriate. Pro Tip: Choosing the established phrase in formal communication helps your writing sound polished and protects your professional reputation.
