Obviously if you can write Mathematica, that's far more precise than any natural language query, but I think it's always been impressively good at it. You wouldn't say that, say, Python or MySQL is good at parsing natural language - but if you plug a query like:
gravitational constant times density of tungsten carbide times the volume of the earth divided by radius of earth squared
into !wa or Wolfram Alpha it will not only represent the parsed tokens as it interpreted them but also return the correct result of 27 m/s^2, without messing with tedious unit conversions. It's trivial to construct incorrect queries, but where Python just says "SyntaxError" !wa will make an attempt.