WWF accepts 105 two-letter words. Here are the 52 that begin with vowels. Learn ’em now so you can lay ’em down later.
Words With A (at the end): BA – DA – FA – HA – KA – LA – MA – NA – PA – TA – YA – ZA
Words With E (at the end): BE – DE – FE – GE – HE – ME – NE – PE – RE – WE – YE
Words With I (at the end): BI – DI – FI – HI – KI – LI – MI – PI – QI – SI – TI – XI
Words With O (at the end): BO – DO – GO – HO – JO – LO – MO – NO – SO – TO – WO – YO
Words With U (at the end): MU – NU – XU
Words With Y (at the end): BY – MY
Also! Here are the 50 that begin with vowels. And, to add up to 105, the three that have no vowels are HM, MM, & SH.
(Definitions for the less familiar of these are here at Mental Floss, and the rest of the list is from the WWF fan site, wordswithfriends.net.)