please tell me why is duplicated the letter z in the plural of quiz.is there any other like that?
thanks a lot.
That will happen with all words ending in /iz/, such as 'whiz'.
If the plural of 'quiz' were 'quizes', it would be pronounced kwyzez, not kwIzes.
You'll find this doubling in a lot of words when they are inflected, though usually not with plurals:
participles: club - clubbed, clubbing; pip - pipped; mat - matted
alternative forms: pup - puppy; kit - kitten, kitty; dad - daddy
Plurals of words ending in one 's' seem to be random in regard to doubling:
gas - gases; bus - buses OR busses.