xkcd – I’m Sorry – By Randall Munroe – http://xkcd.com

Transcript

Caption: It annoys me when people interpret an obviously sympathetic “I’m sorry” as an apology, so I’ve started responding by making it one.

Vocabulary

your fault (n.) /fɔːlt/ If something bad that has happened is your fault, it happened because of you.
annoy (v.) /əˈnɔɪ/ to make someone slightly angry
interpret (v.) /ɪnˈtɜːprɪt/ here; same as “to understand something as”
obviously (adv.) /ˈɒbviəsli/ in a way that is easy to understand or see.
sympathetic (adj.) /ˌsɪmpəˈθetɪk/ showing that you understand and care about someone’s problems
one, here, refers to “an apology”

Sentences 1 to 3 sound pretty normal, but what the man says in sentence 4 breaks the usual expectations of a conversation. When he man says: “I’m sorry” in sentence 2, it is a “sympathetic I’m sorry”, which means that it just shows that he cares about the woman’s mum, not that he his sorry because he has done it.
In sentence 3, we see that the girl understands this “I’m sorry” as an apology, as if he had done it, as opposed to the “sympathetic I’m sorry.”
However, what is surprising is sentence 4. Here, it sounds as if the man had actually done it and that he did mean the first “I’m sorry” to be an apology as opposed to the “sympathetic I’m sorry.”

I’m sorry can be used in different contexts:

apology: I’m sorry I burned down your mom’s house / I’m sorry I broke your watch
to show sympathy: I’m sorry your mom’s house was burned down / I’m sorry you didn’t pass the class, etc.
to address someone: I’m sorry, could you tell me where I can find a nice place to eat around here?
to show you didn’t understand something (informal): […] I’m sorry?
to ask people to make room for you to pass by: when someone is walking through a crowd a people who are not moving, you can hear something like this: I’m sorry… Sorry … Excuse me … I’m sorry …
Can you think of any other uses?