Letters from Aa to Zz are called the alphabet.
There are altogether 26 letters in the English alphabet.
These are the capital letters. Capital letters are also called upper case letters.
These are the small letters. Small letters are also called lower case letters.
Student A says a letter. Student B writes it on the board.
Now Student B says a letter. Student A writes it on the board.
Continue the game until you have written all the letters.