You can't hear the difference between "man" and "men" in English?

I keep thinking that if uneducated labourers from Uzbekistan can learn to speak Russian in a few years, then I should b-y well be able to manage to!

I do GET the difference between Ш and Щ - it's just that I don't really think of them as different sounds.

My stepmother who is Japanese has the same problem with R and L when she speaks English - she doesn't think there is any real difference and has to really focus to pronounce them clearly. Even though to all of us there is a massive difference.