Correct spelling, explanation: quizzes is the plural form of the noun quiz. It should be spelled with the double -z letter, because the -e in quizzes has a short vowel sound. First of all, when creating a plural form of this word, we need to add the -es suffix to the basis, because it ends in a -z (and -z can’t be followed by -s right after it). Then we must double the consonant – there is a rule in English that says consonants in words with short vowel sounds are usually doubled. Therefore, the only correct form is quizzes, not quizes.

Definition of quizzes:
noun, plural of quiz, a test of knowledge
I’ve always been good at quizzes, especially when they involve logic.
Our teacher gave us a few quizzes about Great Britain.

Collocations with quizzes:
Some most commonly used collocations include: to compile quizzes, to hold quizzes, to organize quizzes, to enter quizzes, to win quizzes.
It takes time to compile suitable quizzes for the class.
My kids were bored so I organized some quizzes for them.
My aunt is brilliant: she always wins all the quizzes.

Incorrect spelling, explanation: when creating the plural form of the word quiz, we should be careful – it’s not enough to just add the typical -s suffix. We need to perform two actions. Firstly, we have to add the -es ending to the root. This is due to the fact that -z can’t be followed by -s. Secondly, we must double the last consonant in the basis, which is the -z letter, because of an important principle: consonants in words with short vowel sounds (-e has a short vowel sound) are doubled on a regular basis. It means the only correct form is quizzes, not quizes.