HARRO EVERYNYAN, ai am heaa to tok to yu abart Engrish! Banzai!
Warts dat? I raff I ruse?
Before I explain it, it though it would be best to give you an example. These are two clips I took from the most recent Evangelion Movie, with the Japanese seiyuu (voice actors) speaking in English. Exciting, right? Dear god Kaji...

De anarizis purring da permafrust extrazion...

Excuse me, but what? English is my native language, but without the subs I would probably be lost. Mari, on the other hand, has really good pronunciation for the most part.

Japanese has its fair share of words borrowed from English, but anytime (especially in Animes) they like to stretch the boundaries of languages, it usually turns out bad. For instance, the character Free from Soul Eater likes to cuss out loud repeatedly in English. And of course, any special movie that any character has, ABSOLUTELY must be in English.

"GIGA DORRIRU BUREAKAAAA"
-Simon, Gurren Lagann

Of course, these characters come with such splendid American names. And what great names they are, ones you would normally find in America, such as "Roy Mustang" and "Spike Spiegel" (In his defense, Spiegel is German). I can't imagine what Japanese people think goes on in the United States, especially after the recent release of Heroman, which supposedly takes place o somewhere in California.Typical American kids wearing typical... omfg what is with that hair.

Also what better way to show your affection for someone than by expressing it in broken English?

If you want a list of every possible reference to English that has ever happened in anime, check out the TV Tropes article. (But dear god, do not click any links or attempt to read the whole thing. You will NEVER find yourself back here.)
Yes Kana, you are Boss. (Unlike Andy Samberg)

And of course actual English spoken by gai-jin or "foreigners" in anime sounds something like this:

Pera pera pae, perpera pera pa.

To be fair, "pera pera" means "to be fluent" in Japanese, and a lot of people in Japan are "Eigo pera pera" (Fluent in English), but don't expect every person you walk up to on the street to speak English. You simply need to learn to speak Japanese the right way. Of course, then you would be be committing Japongo. Which is a word I just made up, but it is just as bad.