Are you allowed 2 letter words in scrabble?

Are you allowed 2 letter words in scrabble?

There are 107 acceptable 2-letter words listed in the Official Scrabble Players Dictionary, 6th Edition (OSPD6), and the Official Tournament and Club Word List (OTCWL, or simply, TWL): AA, AB, AD, AE, AG, AH, AI, AL, AM, AN, AR, AS, AT, AW, AX, AY. BA, BE, BI, BO, BY. DA, DE, DO.