Personally I don't have (or I think I don't have) any problem pronouncing "the" as it should be pronounced if it is in the beginning of sentence. However, it is really hard for me to produce same pronunciation of "the" if it is located in the middle of sentence. For example: Close the door. that "the" placed between close and door is killing me specially if I speak a bit fast, it'll be harder. I have watched lots of movies (American&British) and I think even they sometimes pronounce "the" as "de", or at least that sounds to me like that. So, considering all I said, can I simply say: close de door?