A fair overview of common words and phrases in the (mainly Poilisher dialect of) Yiddish. This book won't teach you to speak Yiddish, but is invaluable in understanding and appreciating Jewish humour, some of which features even in Gentile American comedy. Rosten illustrates the majority of the entries with anecdotes and jokes, most of which are very funny indeed.
One thing though; if it's Hebrew you want to know about, well, it's an entirely different language and, as a hebraist myself, I have to say that some aspects of Rosten's notes on Hebrew are rather troubling. But his Yiddish seems sound, and that is, after all, what I bought this book to sample. I did so in 1980, and still dip into it on occaision.
Enjoy!
Aleichem (or, dear Ladies, Aleichen) Shalom,
John Griffiths RGN BD(hons.)