Is there a significant difference between “sorry,” “pardon” and “excuse me”? Are they interchangeable?

Solution 1:

This is complicated. I will describe American English:

Situations where "excuse me" is better than "sorry":

• you are walking through a crowd and need to move. "Sorry" implies that you don't have a right to walk through the crowd and that you are "guilty" of something. "Excuse me" is better. You might say "sorry," if, for instance, you have to push through a crowd in an unexpected way, because you have made a mistake (like, if you are walking "upstream" while others are boarding an airplane.)
• your body inadvertently makes a noise. (you will have to consult an etiquette book for which noises require "excuse me," but from the standpoint of language usage, none of the noises require "sorry," and indeed if you say "sorry" it will sound like you are guilty of something, which in turn seems a little crude.)

Situations where "sorry" is better than "excuse me":

• You have done something wrong, which you regret doing. "Excuse me for getting angry" implies to some extent that you don't regret getting angry very strongly.

Situations where they are interchangeable:

• You don't understand someone, and you want them to repeat what they said.

In general "pardon" and "pardon me" mean the same thing as "excuse me" but are more formal.

Both "excuse me" and "pardon me" can be said in anger, for instance, if someone is standing in your way (see bullet point one under excuse me) and you feel they are being quite inconsiderate and should have realized that they were in the way, you might say "excuse me!" in your angriest voice. But it's much rarer to say "sorry" in anger (except sarcastically, when you are not in fact sorry).