Informal:
* איז דאָס גאָט וויל (iz dos got vil) - This is the most common and informal way to say "God willing".
* וויל גאָט (vil got) - This is another informal way, literally meaning "God wills".
Formal:
* אַזוי וויל גאָט (azoy vil got) - This is a more formal way to say "God willing", literally meaning "so God wills".
Other options:
* מיט גאָטעס הילף (mit gotes hilf) - This means "with God's help", and can also be used to express "God willing".
* איז גאָט ווילען (iz got vilen) - This is a more archaic and formal way to say "God willing", literally meaning "if God wills".
The best way to say "God willing" in Yiddish will depend on the specific situation and the speaker's relationship with the listener.