Formal:
* פֿאַרשטײַסט איר? (farstait ir?) - This is the most literal translation, meaning "Do you understand?" It's a formal way to ask.
Informal:
* פֿאַרשטײסט? (farstait?) - This is a more informal version, dropping the "ir" (you) for a more casual feel.
* פֿאַרשטײַסט מען? (farstait men?) - This means "Do you understand?" but literally translates to "Does one understand?" It's an informal way to ask, suggesting a collective understanding.
* קלאָר? (klar?) - This means "Clear?" or "Is that clear?" It's a more casual way to confirm understanding.
* ביסט אַזוי? (bist azoy?) - This is a more colloquial phrase, meaning "Are you with me?" or "Do you get it?" It implies a closer connection between the speaker and the listener.
In addition to these, you might also hear:
* האָסט איר פֿאַרשטאַנען? (host ir farstanen?) - This is a more emphatic way to ask, meaning "Have you understood?"
* ווײַסט איר? (vaist ir?) - This means "Do you know?" but can also be used in the context of "Do you understand?"
The best choice will depend on your relationship with the person you're speaking to and the tone you want to convey.