"Study abroad" in the Statoin

There are a lot of advertisements of the English cram school in the train or the backside of the tissue. There are a lot of people who commute there as well. They go to NOVA, ECC or Berlitz etc... They study English once or twice a week for about thirty thousand yen. Howvere, these English schools can be healpful for us in fact? I think maybe NO. I have several friends who is one of the NOVA students. He has commuted there for more than several months, but I cannot see his growth in English from my house. If I can be fluently with these schools, everyone would rush to NOVA. In fact, honestly speaking, I have never heard of getting high levels of English in the cram school. We would not be the good English speaker, except going abraod actually.