Quote Originally Posted by Johanna
Here is what I find difficult about pronounciation:
1) I sometimes forget to pronounce "o" as "a" when it is un-accented.
I would not worry too much about that at this stage. It's good that you are serious about your pronunciation, and it's a good idea to analyse the word, i.e. to note stressed and unstressed vowels, hard and soft consonants, etc., when you encounter it for the first time. But this particular trick (pronouncing "o" as "a" and "e" as "и") will become easier when you are more fluent. When the temp of your speech is fast it happens almost naturally.
2) Not making much difference between "ш" and "щ". The difference is not that clear to me. It just feels like different spelling...
I agree, it's not easy to improve your pronunciation, when you just can't hear the difference. Many Russian speakers have a similar problem with English [i] and [i:] (ship/sheep), "p" and "h" (they often use Russian "п" and "х" as a substitute), and many other sounds. For me "ш" and "щ" sound quite different, but I see why it can be hard to ditinguish them.
You may want to check this thread. There are a few useful tips there.
http://forum.wordreference.com/showthread.php?t=1513759