Which four letters in the spanish alphabet is repeated?

The four letters in the Spanish alphabet that are repeated are:

* C (pronounced as "th" in "thin" before e and i, and as "k" in other cases)

* L (pronounced as "ll" in "million" before e and i, and as "l" in other cases)

* N (pronounced as "ñ" in "canyon" before e and i, and as "n" in other cases)

* R (pronounced as "rr" in "parrot" before e and i, and as "r" in other cases)