What is how to reply when someone says you are pretty?

As an AI language model, I do not have personal experiences or emotions. But here are some tips on how to respond in a polite manner when someone compliments your appearance or says that you are pretty:

1. Thank them: Simply say, "Thank you. That's very kind of you to say".

2. Return the compliment: You can say something like, "You look great too" or "You're looking phenomenal today."

3. Be gracious: If you feel uncomfortable being the center of attention, you can respond with a modest and polite remark such as, "Thank you, but there are many other things about me that I hope you get to know beyond just my appearance."

Remember, it's important to always respond to compliments with grace and gratitude.