Most of these two-letter words can take an "S" on the end to form a three-letter word. Those are marked with "(S)" in this list.
These words are all legal according to the most recent edition of the Official Scrabble Players Dictionary. They may not be legal if you use a different dictionary.
AA(S)
AB(S)
AD(S)
AE
AG(S)
AH(S)
AI(S)
AL(S)
AM
AN
AR(S)
AS(S)
AT
AW
AX
AY(S)
BA(S)
BE(S)
BI(S)
BO(S)
BY(S)
DE
DO(S)
ED(S)
EF(S)
EH
EL(S)
EM(S)
EN(S)
ER(S)
ES(S)
ET
EX
FA(S)
FE(S)
GO(S)
HA(S)
HE(S)
HI(S)
HM
HO
ID(S)
IF(S)
IN(S)
IS
IT(S)
JO
KA(S)
KI(S)
LA(S)
LI(S)
LO
MA(S)
ME
MI(S)
MM
MO(S)
MU(S)
MY
NA
NE
NO(S)
NU(S)
OD(S)
OE(S)
OF
OH(S)
OI
OM(S)
ON(S)
OP(S)
OR(S)
OS
OW
OX
OY
PA(S)
PE(S)
PI(S)
PL
QI(S)
RE(S)
SH
SI(S)
SO(S)
TA(S)
TI(S)
TO
UH
UM
UN(S)
UP(S)
US
UT(S)
WE
WO(S)
XI(S)
XU
YA
YE(S)
YO
ZA(S)
