Spelling words isn’t always easy, especially when they contain double letters. In this case, the correct spelling is occurred. How can you remember it when you need it?
The best way to remember how to spell occurred is to remember its double set of double consonants. In English, the final letter is doubled when a word of two or more syllables has stress on the final syllable. Occur fits the rule, so there are two Cs and two Rs in occurred. Would you like to see some examples?