You may say 少し日本語をしゃべるけど、上手じゃありません。 (sukoshi nihongo wo shaberu kedo, jouzu ja arimasen) which would translate into "I speak a little Japanese, but I am not good" in Japanese. You may also use 話す (hanasu) instead of しゃべる (shaberu), though from my experience しゃべる seems to come up more in spoken conversation.
'You have a very good voice' would translate to æŒå£°ãŒã¨ã¦ã‚‚ã„ã„ (utagoe ga totemo ii) in Japanese.
Sayonara .
You may say 'oshare' in Japanese; it means "fashionable," "stylish."
yoi or ii
TOTEMO furui
If you meant to say "konichiwa" then it means good afternoon/good day in Japanese :L
Ohao Gozaimasu.
yoi shokuyoku
Ohayo (OHIO)
Hijo ni kanashii
U ask your mom
This can be translated as "Your Japanese is very good," or "You speak Japanese very well".