[一度]{いちど(ひとたび)}
means once
, but [一遍]{いっぺん}
also mean once
in sentences like once I did something
or once I am a something
.
常に
means always
in sentences like I always am a something
or I always do something
But idiomatically, Once bitten twice shy
is translated as [羹]{あつもの}に[懲]{こ}りて[膾]{なます}を[吹]{ふ}く
in Japanese.
So if I want to say Once a thief, always a thief
, is this phrase grammatical 盗人一度, 常に盗人
?
What if I want to say Once a X, always a X
? and X is a noun/noun phrase?
Once a thief, always a thief
: eow.alc.co.jp/search?q=once+a+thief%2c+always+a+thief