Of course, proper pronunciation of words really does not matter much, but it may leave a bad impression on conscious colleagues. So you will still have to straighten up that tongue.

For starters, here's a guide to the 100 most mispronounced words in the English language. Obviously, these words are often used by people but fail to give the dictionary pronunciation. I hope this helps.

Link: moleskinerie: 100 Most Often Mispronounced Words