Mazel tov is for good things that have already happened.
Yiddish is written with the Hebrew alphabet. For anyone who doesn’t know, Yiddish is baaasically German moved slightly to the left. I need to look into it more, but I’m fucking fascinated to see how that works and to see if it could help me understand the Hebrew alphabet better. Or if it’s just super weird. Edit: it’s really reductionist to call Yiddish German. It is legitimately its own language, with some different grammar rules and a lot of other languages worked in as well. My description was mostly a joke and is a way that I conceptualize it to understand it better.