Most Important Point
In standard spelling, occurrence keeps the double r you see in occurred and occurring.✅Source
If you ever stop mid-sentence and wonder whether it’s occurrence or occurence, you’re bumping into a classic double-letter trap. The noun looks longer than the verb occur, and that extra r is exactly where the confusion lives. This page sticks to the facts: what the word means, how it behaves in grammar, and why the spelling changes.
Meaning and Grammar
Occurrence is a noun used for something that happens or for the fact of happening. It can work as countable (one occurrence, two occurrences) and also as uncountable (the occurrence of something). The plural form is occurrences.✅Source
- Part of Speech
- Noun (not a verb)
- Typical Sense
- An event or happening (sometimes neutral, sometimes technical)
- Plural
- occurrences (keeps double r)
- Common Misspelling
- occurence (missing the second r)
Countable vs Uncountable Use
✅ Countable
Use an occurrence when you mean one specific happening. The focus is on a single instance, even if it’s part of a larger pattern.
- A rare occurrence can still be real.
- We logged three occurrences in the report.
✅ Uncountable
Use occurrence as uncountable when you mean the fact that something happens. This often appears in the pattern the occurrence of + noun.
- The occurrence of typos dropped after editing.
- They studied the occurrence of a sound in different rooms.
Why The Double R
The base verb is occur (with two c’s and a single r). When English adds endings, you’ll often see the r double in related forms like occurred and occurring. The noun occurrence follows the same family pattern, so it keeps that double r look.✅Source
Key Detail The misspelling occurence usually happens because people copy the single r from occur and forget that the noun form expands to -rr-.
Spelling Structure
It helps to see occurrence as a build from the verb occur plus the noun ending -ence. The “problem spot” is the middle: you keep cc and you add the extra r, giving -ccurr-.
What Changes From “Occur” to “Occurrence”
- occur ends with a single r.
- The noun form inserts an extra r to create occurr-.
- Add -ence to finish occurrence (and keep the double c).
Word Family
The spelling gets easier when you look at the word family. English treats occur, occurred, occurring, and occurrence as a tight set. So the “double” letters show up in predictable places across the family, especially the r in the longer forms.
Academic guidance often frames this as a broader spelling pattern: verbs ending in -ur can take a double r when -ence is added, while similar-looking families may not behave the same way (for example, refer becomes reference without doubling r).✅Source
| Form | Role | What To Notice |
|---|---|---|
| occur | verb | cc is fixed; final r is single. |
| occurred | past | Shows -rr- in the family. |
| occurring | -ing form | Keeps -rr-; still has cc. |
| occurrence | noun | The common trap: it needs two r’s. |
| occurrences | plural | Plural keeps the same core spelling: -rr- stays. |
Examples in Context
Most real-world uses put occurrence next to words like common, rare, unexpected, or in the phrase the occurrence of. These examples keep it neutral and clear, with the spelling doing the heavy lifting.
✅ Correct Examples
- The occurrence of small typos is normal in a first draft.
- That kind of weather shift is a rare occurrence here.
- We tracked each occurrence of the alert to see the pattern.
- The report focuses on the occurrence of certain sounds in speech.
❌ Incorrect Examples
These are the same ideas, but the spelling occurence drops the second r. That’s the only difference, and it’s the one that matters.
- The occurence of small typos is normal in a first draft.
- That kind of weather shift is a rare occurence here.
- We tracked each occurence of the alert to see the pattern.
Occurrence and Similar Words
Occurrence is broad. It can label almost any happening without adding a lot of extra meaning. Words like event, incident, or episode can feel more specific depending on context, but occurrence stays general and flexible.✅Source
Common Technical Use In research, logs, and analytics, occurrence often pairs with frequency, rate, or count. The word stays the same; the surrounding nouns explain the measurement.
Etymology and History
Historically, the word is linked to French and Latin forms built on the idea of coming up or presenting itself. That background fits the modern sense: an occurrence is simply something that turns up or happens, without forcing a stronger label than you need.✅Source