Learn Turkish: Kağıda bir cevap yazıyorum. - I am writing an answer on the paper.

This is a perfect example of consonant mutation! When we add the vowel suffix -a to kağıt, the hard t softens to a d to make it easier to pronounce.

Why do we use the ending -a (to) for kağıda instead of the location ending -da (on)?

In English, we write on paper. But in Turkish, the verb yazmak (to write) implies directing your words to the paper. Because there is a direction involved, Turkish uses the dative suffix -a (to/towards) instead of the locative suffix -da.

The word cevap ends in p. Will that ever change to a b?

Yes! Because of consonant mutation, the p would change to a b if we added a suffix starting with a vowel, like if we wanted to say my answer (cevabım). In this sentence, cevap stands alone with no suffix, so the p stays exactly as it is.

How do we build the verb yazıyorum?