What can and cannot be asked when talking to foreigners?

Don’t ask: The girl’s age. Remember not to hold back. Just say what you want. Foreigners are more sensitive to certain topics: marriage, age, personal privacy, etc. Remember to look into the eyes of foreigners when speaking to them, otherwise you will be considered rude. As for the starting point of the topic, you can choose an innocuous question like the weather. Here are some examples I found online.