Przepraszam is a magic word in the Polish language, because it's a very polite and very useful one. You can use it instead of an English expression "Excuse me", but also instead of English "I'm sorry". The meaning depends on the situation. Let's see some examples:
You should say "Przepraszam", when you are going to interrupt someone and ask about something, for example when you are asking someone to show you the way.
When you are asking an unknown woman, say - "Przepraszam panią" (Excuse me, Madam). When you are asking an unknown man – you should say "Przepraszam pana" (Excuse me, Sir).When you are talking to a child or a friend you can use an informal expression
How to say "Exuse me" & "I'm sorry" in Polish. 
