When talking about requests, permission, favours and asking for information should I use "please" in my sentences with both can and could?
1."Can/could we look words up in a dictionary, please?"
- "Can/could I speak to Gerry, please?"
3."Can/could I have your passport, please?"
4."Can/could I have my passport, please?"
5."Can/could I have these postcards, please?"
6."Tom, could/can I borrow your umbrella, please?"
7."Can/could you open the door, please?"
8."Can/could you wait a moment, please?"