As you can probably guess, the letter Z is the least commonly used letter in the English alphabet. (In American English, this letter is pronounced “zee.”) The letter Q is the second least commonly used letter. In English words, Q is almost always followed by the letter U. The letters QU form a digraph. A digraph is a single sound made from two successive letters. When playing word games like SCRABBLE, many players dread the letter Q. Not only is it difficult to think of words that contain this rarely used letter, it is almost always necessary to have a tile with the letter U in order to play a Q. After all, most words that contain a Qq without a U are proper nouns like Iraq and Qantas, which are not permitted. Some loanwords from other languages are permitted in word games. In fact qi, also spelled c-h-i, is the most commonly played word in SCRABBLE tournaments.