There are 26 letters in the English alphabet.
There are 5 vowels: A, E, I, O and U. The rest of the letters are consonants.
Practise reading the letters out loud:
Capital letters (upper case letters):

ABCDEFGHI
JKLMNOPQR
STUVWXYZ

Small letters (lower case letters):

abcdefghi
jklmnopqr
stuvwxyz