aho = dumb
ai = love
aieru = i love you
aku = evil
akuma = devil
ame = rain
ani = big brother
anata baka? = are you stupid?
ano = um...
are = oh my!/WTF!
arigato = thank-you
arigato gozaimasu= thank you very much
aa = tomorrow
atashi = me [female version]
baka = stupid
bishoujo = young attractive girl
bishounen = young attractive boy
boku = me/ I [male version, imformal]
che = (to express disgust)
chan = suffix for a name that means family or close friend. (ex. Sakura-chan)
chotto = a little
Daijoubu = in question means "are youok?", statement is "I'm fine."
dame = stop/no
dare = who
demo = but (start of sentence)
doko = where
doe = why
dozo = thanks
gakkou = school
gakkousei = student
goku = quiet
gomen = sorry
gomen naisai = i'm very sorry
hai = yes
hanyou = half demon
hayaku = hurry
hime = princess
houshi = monk
= ert [or another thing I shall not mention]
Iie = no
ikari = anger
itai = ouch
inu = dog
isshoni = together
itadakimasu = said before eating a meal [bon appetit of Japan]
ja ne = later! 
Kami or Kami-sama = God
kaitou = theif
katana = sword
kawaii = cute
Kisama = you or bastard
kizu = pain/hurt
koi = lover
koibito = boyfriend or girlfriend
kokoro = heart
koneko = kitty
konnichiwa = hello
kuniochi = female ninja
kuso = damnit
matte = stop
me = eyes
minna = everyone
nande = why
nani = what?!
ne = right?
neko = cat
ohayo gozaimasu = good morning
Oi! = hey [male]
omedetou = congratulations
okashi = sweets, candy, ect.
ongaku = music
onegai = please
oniisan (niisan)= big brother
ore = I (rude way of saying it)
otou-san = father
oyasumi nasai = good night
sake = wine
sayonara = good bye
shin-e = die
sugoi = cool, awesome!
summimasen = i'm sorry, excuse me
taidaima = i'm home/i'm back
tobira = door
toki = time
tomodachi = friend
tooi = far
urusai = Shut Up!
uso = a lie

uta = song
utau = sing
wakatta = i understand
warai = smile/laugh
watashi = I
yamero = stop it
yaro= bastard [towards males]
yuugi = game/play

Colors:

Aoi: Blue

Akai: Red

Chairoi: Brown

Haiiro: Grey

Kiiroi: Yellow

Kuroi: Black

Midori: Green

Murasaki: Purple

Orenji: Orange

Shiroi: White

 

Numbers:

Ichi: One

Ni: Two

San: Three

Yon/Shi): Four

Go: Five

Roku: Six

Nana/Shichi: Seven

Hachi: Eight

Kyuu: Nine

Juu: Ten

 

Name Suffixes

-chan: Used between friends or with someonne younger than you. Generally a very friendly suffix such as "Shippou-chan". Used between boyfriends and girlfriends.

-kun: Generally used for males, but can bee used for females too. Someone who's close to you as a friend.

-san: Polite and formal. Used for someone at the same position as you or higher. You would use this with strangers if you didn't know them well. It basically means "Ms, Miss, Mr., or Mrs."

dono: Not frequently used in this anime, but in others, like Rurouni Kenshin. Indicates respect and is very polite.

-sama: Very high respect. Used when speakiing about gods or someone like an emperor or king. 
-sensei: Originally means "born earlier than me". Usually used towards your master, teacher, or someone wise in the literature and art. You would call your school teacher by this suffix.

onee-chan/san/sama: What you would call your sister.

onii-chan/san/sama: What you would call your brother.

jii-chan/san/sama: Grandfather. 
Common Phrases
Hajimemae? = how do you do
Genki desu, arigatou = fine, thanks
Anata ha Dousuka? = how about you?
Anata ha? = and you?
Chotto Matte Kudasai = wait a minute/wait
Dare desu ka? = who is it?
Doko desu ka = where is it?
Ikura desu ka? = how much is it? 
Itte Rasshai = take care, come back soon/again
Nan desu ka? = what is it?
O genki desu ka? = how are you?
Okaeri Nasai =welcome home