YOU SAID:

i gotta go water my fingernails

INTO JAPANESE

爪に水をやらなきゃ

BACK INTO ENGLISH

I have to water my nails

INTO JAPANESE

爪に水をやる必要があります

BACK INTO ENGLISH

You need to water your nails

INTO JAPANESE

あなたはあなたの爪に水をやる必要があります

BACK INTO ENGLISH

You need to water your nails