Formal:
* 歡迎 (huānyíng): This is the most common and formal way to say "welcome."
* 歡迎光臨 (huānyíng guānglín): This is another formal way to say "welcome," often used in businesses or for guests.
Informal:
* 歡迎 (huānyíng): This is also used informally, but the tone will be more casual.
* 你好 (nǐ hǎo): This means "hello" but can be used to greet someone and also conveys a sense of welcome.
* 回來啦 (huílai la): This literally means "you're back," and it's a casual way of welcoming someone back to a place.
Note: It's always best to err on the side of formality in Taiwan, especially when interacting with strangers or people in positions of authority.