Some Pokemon games have a specific person you can talk to that will tell your Pokemon's happiness, some Pokemon games show there happiness after giving them an item the closer they get the happier they are.
Go here for everything you wish to know about how to raise happiness in any Pokemon version: http://bulbapedia.bulbagarden.net/wiki/Happiness
haha
Happiness is gained by taking care of your pokemon giving it items, training it and many more things. Once it's happiness reaches the max happiness have it level up to evolve the pokemon.
Yes, it increases a Pokemon's happiness. It's recommended to use massages if you're trying to evolve a Pokemon that evolves by happiness.
Southeast of Pastoria, Doctor footstep will give you a few sentences about how your Pokemon feels about you. If your Pokemon really likes you he will give you the footprint ribbon.
You can check a Pokemon's happiness at a game's happiness checker. Where the person is located depends on the game you are playing.
A certain person in verdanturf town will let you know your pokemon's happiness.
Go here for everything you wish to know about how to raise happiness in any Pokemon version: http://bulbapedia.bulbagarden.net/wiki/Happiness
haha
when you talk to it if it has six hearts around it that means its at max happiness
I know that togetic does....you should check serebii
I have to know first which pokemon game are you talking about. Edit the category so that I can see and then I can answer.
It shows how much the Pokemon is happy with you. In some Pokemon you can evolve it if it has high happiness.
with raising the Pokemon with that Pokemon for many time You can raise your Pokemon happiness by defeating many trainers with Pokemon do you want to raise.
Happiny (at full happiness) thats all i know. there might be more
Maxing out the happiness of a pokemon is somewhat time consuming. Walking around with the pokemon in the lead position will help slowly increase the happiness. You can also feed the pokemon poffins to help raise stats and happiness.
you can check a pokemons happiness in Diamond/pearl by the use of a poketch app, in previous games you could only know in the happiness was maxed by obtain a ribbon from a certain character depending on the game.