The second PROLOG assignment:

Write a context sensitive parser that takes sentences and decides
whether they are in correct english; a specification for such a 
program is in the course notes on pg. 420.  You should add to this
the capability to handle adjectives, adverbs, prepositional phrases
and compound sentences (and, but).

Must do inheritance for a possible A.

Other A-grade work that goes above and beyond this could include 
relative clauses (that, which, etc.), pronoun reference (this is
a hard one), and so on.