We have an indoor cat but occasionally she wants to go outside. Her way of asking is to walk to the door and put her paw up on the wall and wait for us to open the door.
We adopted a chug and didn't really his background. On day two when we came home he got so excited that he started talking. Scared the crap out of me at first but now it's normal. He can be noisy when he gets going so we tell him "too loud" and he will lower his voice.
The chihuahua we found on our road has me trained. She whines and I pick her up and put her in my shirt. She pokes her head out the neck and we watch tv.