Turing test isn't just a natural language problem. It is far more complex and requires context awareness and emotional intelligence far beyond where we are currently. Language recognition has been at the forefront of research for at least 30 years and it has improved significantly. However, the turing test aspect has only minimally improved.

Edit: iopq, pretending to be a dumb human (or one with a language barrier) is cheating for a headline. A real Turing test would require a computer imitate a human for longer than 5 minutes (although currently that is plenty of time) and without any caveats or limitations on the computer's skill.

Yes, it is very hard challenge, even for 5 minutes. Still, I think we will see some significant progress soon.

That's easy. Just pretend to be a really stupid human. It's been done before.