You talk with your mom about giving your money to her so she can save it. This is so you don't lose your money if you lose battles
You get the pokegear from your mom after you talk to prof elm.
They can't talk, but they can express emotions.
Ask your mom to save your money, and if your lucky, she will buy a moon stone with your money, and it will be in the Pokemart, just talk to the guy near the registry.
Find out about their mom and talk about her.
you talk to a man in pewter
talk with a nerd in lavender town
Talk to it.
talk to ramdom people
you give her a sun stone and trade her
go to the gym and talk to the guy
If your riolu is following you in heartgold or soulsilver you can talk to it.
You walk up to him and press A.