something nice = epes simpatisch (עפּעס סימפּאַטיש)
The Yiddish translation for smart person is "חכם" (khokhem).
In Yiddish, the word "Nebish" means an awkward person, or nerd.
In Yiddish, a Schlimiel is a person who can't do anythng right; A Schlimazel (or Schlamazel) in Yiddish, is a person who fails at everything and is thought to be very unlucky.
לאנדסמאן - Landsman
It is not a problem
"Alter mensch."
The Yiddish word for a clumsy awkward person is "shlemazel." It is often used to describe someone who is unlucky or accident-prone.
Mentsh is probably your best bet. It means a good, honorable, decent person and can be applied to anyone whether male, female, adult or child.You can also refer to someone as ehrlich, meaning upstanding and honest.
In Yiddish, a good deed is usually referred to with the Hebrew word, "MITS-vah".
mushuganah (as in a crazzy person :P) ~chachi
Yutz n. (Yiddish) -- a vulgar and unappealing person.