My friend, who is English, said that the words like cut, duck, etc. should be pronounced 'kut', 'duk' because there is no 'a' in them. I told him it was probably his accent (south Yorkshire) but he said it was not and gave me an example of his accent: 'sun' - son, 'munday' - Monday, 'sumthing' - something etc. So I'm still struggling with words with 'u'.
By the way, I love that accent, sounds nice