Informal:
* สวัสดี (sa-wat-dee) - This is the most common and general greeting, similar to "hello" in English. You can use it with friends, family, and people you know well.
* หวัดดี (wa-dt-dee) - This is a more casual and shortened version of "สวัสดี," often used among close friends.
Formal:
* สวัสดีครับ (sa-wat-dee krap) - This is the polite form of "สวัสดี" for men. You use it with strangers, older people, and anyone you want to show respect.
* สวัสดีค่ะ (sa-wat-dee kha) - This is the polite form of "สวัสดี" for women. You use it with strangers, older people, and anyone you want to show respect.
Other options:
* ยินดีที่ได้รู้จัก (yin-dee tee dai roo-jak) - This means "Nice to meet you" and is a good option for meeting someone new.
* สบายดีไหม (sa-bai dee mai) - This means "Are you well?" and is a common greeting in informal settings.
Remember to pronounce the tones correctly in Thai, as this can affect the meaning of the word.
The best way to learn how to say "Hi" in Thai is to practice with a native speaker or use a language learning app or website.