See, thats alot harder. It would have to have a dumb base, like if I type "I like cheese." it runs through a condition and responds, "Cheese is stinky."
But then it would have to be able to understand parts of a sentence, so if you say "I like cheese" the program would go "I" so the're saying something concerning themselves, "like" positive with some sort of definition that was understandable by the program, and "cheese" the subject matter, the point of the sentence. With all this a smart bot then has to generate a unique answer bases on its programming, so...
osistlk: I like cheese.
smartofartobot: Cheese smells so I don't like it.
This is explained as it were somewhat easy but my advice would be to build your way up from dumb bots to smart bots.