Hi david,
That's what languages are all about. All too often you will just sound like "a nice guy" when speaking in another language, b/c that's all you've been taught. Read comics, watch TV and movies without reading the subtitles, hang out in your local pub, listen to the songs' lyrics, read English books if you enjoy it, participate in forums on the Internet, or, if you like to mix business and pleasure and you want real fast results: find an english-speaking girlfriend
FRC