Correct spelling


Correct spelling, explanation: this is the regular form of Past Participle verb refer. It comes from the Latin word referre. Initially, the word appeared in late Middle English as referren. Now it is nearly unchanged. Therefore, the correct form is referred with single f and double r, not reffered.

Definition of referred:
verb, past participle form of the verb refer meaning to mention or to look at for information,
I like this book because the author referred to Shakespeare, my favorite poet.
I referred to your notes in order to find the name of my plant.

Incorrect spelling


Incorrect spelling, explanation: this is the basic rule that we double the consonant and add suffix ed when we pronounce the final syllable of a verb with the stress. Thus, as the syllable fer is stressed, we have to double consonant r. However, learners confuse which consonant should double and write two f instead of two r‘s. As a result, this form reffered is incorrect.

Incorrect spelling


Incorrect spelling