“Yiddish for dummies” is also based on Yiddish as it was a century ago, when most Americans who spoke Yiddish were secular (or at least “otd” as we now say). A major change is the American English and Israeli (zionist) Hebrew have replaced German and the Slavic languages as major influences on vocabulary and grammer. Also, modern 21st century Yiddish is a lot “cleaner” (reflecting the usage among hareidim).
