Two-letter Scrabble words

Yo! From the Official Scrabble Players' Dictionary (official for America only, btw), here is a list of the words that you can make when you have no other options, when you feel like being a two-year-old, when you need to rack up a bajilion points with one well-placed "X", or when you're feeling pedantic and want someone to challenge your word so you can take an extra go on that triple word score square. Tournament players have this list memorized; world-class players do the three letter Scrabble words as well. There are some who have even learned the four letter words--and your mother told you what happens to people who learn too many four letter words, right?

But I digress. Here, for your Scrabble pleasure, morbid curiosity, and your burgeoning vocabulary, it is:

AA	rough, cindery lava

AB	abdominal muscle

AD	advertisement

AE	one (UK)

AG	pertaining to agriculture

AH	interjection expressing understanding

AI	three-toed sloth

AL	East Indian tree

AM	be, conjugated: to exist, 1st person

AN	indefinite article

AR	the letter 'R'

AS	to the same degree

AT	in the location of

AW	interjection expressing disbelief

AX	to cut with an ax

AY	aye, yes

BA	eternal soul in Egyptian mythology 

BE	to exist

BI	bisexual

BO	pal

BY	side issue

DE	of, from

DO	to execute/first tone of musical scale

ED	education {OSPD3}

EF	letter 'F' 

EH	interjection used to indicate lack of understanding 

EL	letter 'L'

EM	printer's measurement

EN	printer's measurement

ER	interjection expressing hesitation

ES	letter 'S'

ET	ate

EX	letter 'X'

FA	fourth tone of diatonic musical scale 

GO	to leave 

HA	sound expressing triumph

HE	male person

HI	interjection used as a greeting

HM	interjection expressing thought 

HO	interjection used to attract attention to something

ID	part of psyche related to instinctual impulses 

IF	possible condition

IN	influence

IS	to be, third person

IT	person playing tag/indefinite pronoun

JO	sweetheart 

KA	Egyptian spiritual self 

LA	sixth tone of diatonic musical scale

LI	Chinese unit of distance

LO	interjection used to attract attention

MA	mother 

ME	pronoun referring to myself

MI	third tone of diatonic musical scale

MM	interjection expressing satisfaction

MO	moment

MU	Greek letter

MY	possessive prounoun

NA	no 

NE	born with the name of (nee)

NO	negative reply

NU	Greek letter

OD	hypothetical force of natural power 

OE	Faroean wind

OF	coming from

OH	exclamation

OM	mantra used in meditation

ON	not off

OP	style of abstract art

OR	the color gold, esp. in heraldry

OS	orifice/bone/ridge of sand (esker)

OW	interjection expressing sudden pain

OX	hoofed mammal/clumsy person

OY	interjection expressing dismay

PA	father 

PE	Hebrew letter

PI	Greek letter

RE	second tone of diatonic musical scale 

SH	interjection used to urge silence (shh) 

SI	seventh tone of diatonic musical scale (also: ti)

SO	fifth tone of diatonic musical scale

TA	thanks 

TI	seventh tone of diatonic musical scale

TO	toward

UH	interjection expressing hesitation 

UM	interjection expressing hesitation

UN	one

UP	to raise

US	objective pronoun for "we"

UT	musical tone in French solmization system

WE	plural pronoun 

WO	woe

XI	Greek letter 

XU	Vietnamese monetary unit

YA	you 

YE	you

YO	interjection used to call attention 

The slightly longer list of the 106 permissible two-letter words for British tournament Scrabble use, drawn (but not cut and pasted) from the Chambers dictionary: definitions given for words not in the American list. These are rather more important in cutthroat competition (whether it be in tournaments or against your SO's grandma) than Jurph suggests, since they enable new words to be played alongside others to create multiple scoring opportunities:

aa
ad
ae
ah
ai
am
an
ar
as
at
aw
ax
ay
ba
be
bo - the sort of tree under which Buddha found enlightenment, or US slang for a bloke
by
ch - south western English dialect form of 1st person subject pronoun
da - father (dialect) and a Burmese knife
di - plural of deus
do
ea - river or drainage channel
ee - eye (Scottish)
ef
eh
el
em
en
er
es
ex
fa
fy - = fie, expression of disapproval
gi - what you wear to do judo
go
gu - a type of viol played in Shetland
ha
he
hi
ho
id
if
in
io - a cry of invocation, joy or despair (in various standard translations of Greek drama, I think)
is
it
jo
ka
ko - a Maori digging-stick
ky - a cow (Scots, the singular of kine)
la
li
lo
ma
me
mi
mo
mu
my
na
ne
no
nu
ny - variant spelling of nigh
ob - an objection (archaic lawyer's slang)
od
oe
of
oh
oi - interjection as in "oi, you, why are you playing that poncy game?"
om
on
oo - Scots dialect forms of "wool" and "we"
op
or
os
ou - Scottish interjection expressing consent (variant of "och")
ow
ox
oy
pa
pi
po
re
sh
si
so
st - a noise you make to attract someone's attention
ta
te - musical note in the tonic sol-fa (same as "ti")
ti
to
ug - to arouse or feel loathing
um
un
up
ur - um, er, ...
us
ut
we
wo
xi
ye
yo
yu - a form of jade
zo - a cross between a yak and a domestic cow, also "zho".

Words found in the American list but not included in the British one: ab, ag, ed, et, hm, mm, pe, uh, xu, ya. Note that in international tournament Scrabble in English, the official British and American lists are combined.

No indication of comparative merit is intended for this list, and my views on playing Scrabble on a never-mind-the-meaning-just-look-at-the-points basis concur largely with dannye's here. This list is drawn from the second edition of Official Scrabble Words; I think there is a newer version based on the current edition of the Chambers dictionary, which certainly has an entry for xu - /msg me if you know of updates. And remember, there are no two letter words with a V in them.