别傻傻地以为speak for yourself是“为自己代言”!
假如听到别人对你说:Speak for yourself. 可千万别傻乎乎地以为他是要你“为自己代言”!
它的意思是“那是你的想法,我可不这么想”。
speak for itself/themselves表示“不言自明,有目共睹”:
The results speak for themselves.结果不言自明。
speak one's mind的意思是“说出心里话,直抒胸臆”:
Can I just speak my mind, even though you probably won't like what I have to say?
我能直抒胸臆吗?你可能不喜欢我要说的话。