Why "occurred" needs two "r's: a spelling insight

What kind of error is it?

Spelling error

Why do people make this mistake?

The word "occurred" is often misspelled as "occured" because people forget to double the "r" when adding the "-ed" suffix to the base verb "occur". This mistake stems from the fact that many English words do not require doubling the consonant when forming the past tense.

What is correct?

"Occurred" is the correct spelling. The word "occur" has the stress on the second syllable ('cur"), which ends with a single consonant "r". According to the spelling rule, when adding the suffix "ed", the final consonant is doubled because it is preceded by a stressed short vowel. This is why the correct spelling is "occurred" instead of "occured".