Well, I think the main problem is the lack of practice. I mean, lot's of Russians when they have a chance to speak English in daily life do it as if they still were at the exam in front of a strict teacher. I've always been a slacker so my English will never be impackable (I've put up with it) but thank God I've spent many hours speaking to Americans, English guys, Australians, Canadians etc. I go on making stupid mistakes but my speach is natural and fluent now.
Another problem is outdated textbooks that are used at schools and universitites. They're really effective and well structured and I do believe that they can't be replaced by modern colourful editions but one should be careful using some phrases from these books unless they don't want to be considered a 90-year-old fa... person. I've been in such situation a few times myself))
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Strength and a beautiful sound like in the tautness of a bow. I want to live like this until the day I die