My wife was a bit worried that her English would not be good enough when she came to the live here last year. Her English is very good and I have no problems understanding her.
It was until we went out to our local in UK that and the blank expressions she got from friends not quite understanding her English that she realised she'll have to adapt a bit.
Over a year later of living and working here, her English has improved greatly, she now even remembers to pronounce the last letter of each word!
I guess what I'm saying is English course are a good foundation but until you get out there and converse with natural English speakers will you pick up English English