Spoken English???

Speak English as often as possible--preferrably, with those for whom it is their native language, or a second language in which they have acquired a demonstrable fluency. Encourage them to correct your speech.

I'm not sure how it works with other languages. I work with a lot of people for whom English is a second language, and I know that a lot of us native English speakers (myself included), have a tendency to mimic the broken English of the people we're speaking to. I even do it with my fiance, but that's in part to make myself understood considering her limited English vocabulary. As Set stated, encourage people to correct your grammar, and also encourage them to speak correctly themselves. Cheers

No mine is terrible.You will just have to put up with it like the rest of use foreigners.That is if you are foreign.I always put an a when the word is a vowel.

What Set and Wilso said. Bear in mind, English is a complicated language if you wish to master all the slang terms that are used. You will pick these up as time goes by, though. Don't get discouraged; I have spoken nothing but English all my life and I still don't get all of it. Keep practicing, and you'll be holding fluid conversations in no time. If you want some extra help, I'm sure some tapes or videos can be found online.