@High Seas,
Factually this has absolutely nothing to do with the "P vs NP" problem.
By definition, an NP problem is a problem whose solution can be verified quickly (i.e. in polynomial time). This means that once you have a potential solution, it is easy to tell if you got it right or not (the problem being coming up with the solution to verify in the first place). Examples of this are finding factors (getting them is difficult, but showing they are the right factors is easy), or finding a quicker route between cities.
Parsing sentences does not have this property. The problem here is that to understand the sentence, you need to have an understanding of the underlying meaning.