"Annoy:" means:
To make someone slightly angry or upset:
- I know you’re doing this only to annoy me.
"Irritate:" means:
to make someone angry or annoyed:
- After a while her behaviour really began to irritate me.
"Bother:" means:
to annoy or cause problems for someone:
- The noise was beginning to bother us, so we left.
To me, when someone gets: "annoyed" or "irritated" or "bothered", an unpleasant stimulant has distracted his/her tranquility, comfort or peace of mind.
The only distinguishing factor that comes to mind is that **"irritate" sounds a bit more formal than the other two for everyday speech and people tend to use it mostly in written English as an alternative for "annoy" and "bother".
All that said, I wonder if you could help me to know what word is more appropriate in each one of the sentences below.
Also please let me know why do you think that way, so that I could find out how do they sound to you.
- He is a very kind and considerate man, but I don't know why he treated us like that at the party! His behavior really ................ me.
a. annoyed
b. irritated
c. bothered
- Excuse me sir. Does my cigarette's smoke ............... you?
a. annoy
b. irritate
c. bother
- It's too hot in the train! I know that it's windy outside, but would it ............... you if I open the window for a couple of minutes? [Said a man to his roommate]
a. annoy
b. irritate
c. bother
Note: for me all three choices mean pretty much the same thing in all scenarios above and can be used interchangeably.