Formal:
* अध्यापक (Adhyāpak) - This is the most formal and respectful way to refer to a teacher.
* गुरु (Guru) - This word literally means "teacher" but also carries a sense of spiritual guidance and mentorship.
Informal:
* टीचर (Tīchar) - This is a more casual and common way to say "teacher".
* मास्टर (Māstar) - This word is used in some regions and is considered informal.
When addressing a teacher directly, you can also use:
* आप (Āp) - This is a respectful way to address someone, similar to "you" in English.
* सर (Sar) - This is a respectful way to address a male teacher.
* मैडम (Ma'dam) - This is a respectful way to address a female teacher.
So, you could say:
* आप अध्यापक हैं। (Āp adhyāpak hain.) - You are a teacher.
* मेरे गुरु (Mere guru) - My teacher
* टीचर साहब (Tīchar sāhab) - Teacher sir (male)
* टीचर मैडम (Tīchar ma'dam) - Teacher madam (female)
The best way to say "teacher" depends on the situation and who you are talking to.