영어 Slang of the Day #18: "Speak for yourself," I think otherwise. What?
You can say "Speak for yourself" when you have a different opinion
Sometimes, another person states an opinion, and you do not agree. When that occurs, you can use the phrase, "Speak for yourself." My guess is that the full sentence would be, "You are speaking for yourself only." It means that you are telling someone that the opinion that he stated is his, and not yours. It is, in a way, a relatively neutral way of saying that you think/feel differently.
A. Everyone knows that actors on Boys Over Flowers are all cute.
B. Speak for yourself. I think they all look too feminine, even though they are male.
A. Jazz music is the most soothing for the soul.
B. Speak for yourself. I think that the Wonder Girls have the most meaningful songs. (?!?)
The point of using "speak for yourself" is that it is a more subtle, and maybe polite, way of saying that you do not agree. However, the language is still slang, and therefore, informal by nature. The examples above wouldn't be used in a business setting or a debate in a formal setting. Of course, if the tone used was more harsh, then "speak for yourself" could be seen as an insult.