「wanna」と「want」の違いは何ですか?

You might have heard or seen the word "wanna" somewhere, like the Cyndi Lauper song:

http://www.youtube.com/watch?v=OTtelwOgscM

Notice that the Youtube page says "Girls just wanna have fun!" but in the video it says "Girls Just Want to Have Fun".

So, usually "wanna" means "want to". It's basically incorrect, and you shouldn't really use it unless you are writing dialogue. However, even when we use it, we have to follow some basic grammar rules. Remember, if you use a singular third person noun, you have to add "s" to the verb. That means:

× What he wanna do in the future is...
○ What he wants to do in the future is...
× My friend wanna go to that restaurant.
○ My friend wants to go to that restaurant.

These are OK, though, as long as you are talking and not writing:
○ I wanna take a vacation! <- first person, so no "s" = I want to take a vacation.
○ They don't wanna see that. <- third person singular, so no "s" = They don't want to see that.
○ We wanna go home! <- again, no "s" is needed = We want to go home!

Now, I wanna eat this chocolate! It's 86 percent cacao -- my favorite! Have a good weekend!