I believe in order to really answer your question; it will take many more years of research in neuroscience, computer science, psychology, and chemistry. Even within this thread itself, how can you be so sure that there are intelligent beings parsing the thread who know english. One would have to clearly define what it truly means to know something. Well, we philosophically understand knowledge as something we have personally experienced empirically, which is known as a posteriori knowledge, or a priori knowledge , that is knowledge that is not from direct personal experience. But who can really deny that there is such a mechanism for a computer to experience things in their own way of experiencing, that which is to be experienced.
The true crux of the problem is that we can't experience another conscience empirically except that of our own, that is, with today's current technology, which is also to say a priori. And yet even our own consciences is mysterious to us, because it does not directly present itself to you as you would normally perceive an entity. When you do perceive an entity, you are using your very conscience, and so, how do you begin to perceive that which gives you the ability to perceive in the first place.
What is essential to remember that just because one has not experienced something yet, does not imply that it will not be experienced. Who is to say that there are not even greater forms of AI, then that of our own Intelligence? What would be so inherently special about our species, that we would experience the "greatest" kind of "intelligence" that we have, that could not somehow be emulated outside of the constructs of nature.
I recommend reading the following philosophical book, that I myself have currently started reading. Sein Und Zeit von Martin Heidegger, that is "Being And Time", and there is an english translation for it.