Hi Sue. It seems that the chat feature only works on a computer/laptop reddit OR on the reddit app on your phone. You may need to do a password reset via reddit so that you can use the same account on your laptop. You can search on google how to reddit password reset and it should be fairly straight forward. Also you are correct. You won't know unless they respond back. If they respond to your chat message, you will get a notification on reddit. Let me know if you are still unclear.