For all intents and purposes "but" is a negation, which goes backwards. "He is a nice guy, but..." ~= "He is not a nice guy, because..." One interesting thing

For all intents and purposes "but" is a negation, which goes backwards. "He is a nice guy, but..." ~= "He is not a nice guy, because..." One interesting things is that when you look at sentiment of words in reviews, the word "but" glows (in red).