For a simple "are" as in "Are you happy?":
* เป็น (pen) - This is the most common and versatile way to say "are". It's used for almost any situation where you're asking or stating something about a state of being.
For "are" as a part of a verb:
* You usually don't translate "are" directly in this case. Instead, you would use the verb conjugation that implies "are".
Examples:
* คุณเป็นคนไทยไหม? (khun pen khon thai mai?) - Are you Thai?
* ฉันเป็นคนใจดี (chan pen khon jai di) - I am a kind person.
* เขากำลังทานข้าวอยู่ (khao gamlang than khao yu) - They are eating rice. (The verb "ทาน (than)" implies "are" in this context)
Let me know if you have a specific sentence in mind, and I can help you translate it!