Informal:
* Ja: This is the most basic and common way to say "yes" in German, often used in casual conversation.
* Klar: This means "clear" or "of course" and conveys a more enthusiastic agreement.
* Genau: This means "exactly" and can be used to express agreement or confirmation.
* Stimmt: This means "correct" or "true" and can be used to confirm something.
* Sicher: This means "sure" or "definitely" and expresses strong agreement.
* Jo: This is a slang term that's similar to "yeah" and is very informal.
Formal:
* Jawohl: This is a more formal way to say "yes" and is often used in military or official settings.
* In der Tat: This means "indeed" or "in fact" and conveys a more formal agreement.
The best translation for "yeah" will depend on the specific context and the level of formality required.