Natural Language Processing with Python

Exercises

1. ○ What constraints are required to correctly parse word sequences like I am happy and she is happy but not *you is happy or *they am happy? Implement two solutions for the present tense paradigm of the verb be in English, first taking Grammar Example 9-8 as your starting point, and then taking Grammar Example 9-22 as the starting point.

2. ○ Develop a variant of grammar in Example 9-17 that uses a feature COUNT to make the distinctions shown here:

   Example 9-60. 

   1. The boy sings.

   2. *Boy sings.

   Example 9-61. 

   1. The boys sing.

   2. Boys sing.

   Example 9-62. 

   1. The water is precious.

   2. Water is precious.

3. ○ Write a function subsumes() that holds of two feature structures fs1 and fs2 just in case fs1 subsumes fs2.

4. ○ Modify the grammar illustrated in Example 9-32 to incorporate a BAR feature for dealing with phrasal projections.

5. ○ Modify the German grammar in Example 9-59 to incorporate the treatment of subcategorization presented in Extending a Feature-Based Grammar.

6. Develop a feature-based grammar that will correctly describe the following Spanish noun phrases:

   Example 9-63. 

   un	cuadro	hermos-o
   INDEF.SG.MASC	picture	beautiful-SG.MASC
   ‘a beautiful picture’

   Example 9-64. 

   un-os	cuadro-s	hermos-os
   INDEF-PL.MASC	picture-PL	beautiful-PL.MASC
   ‘beautiful pictures’

   Example 9-65. 

   un-a	cortina	hermos-a
   INDEF-SG.FEM	curtain	beautiful-SG.FEM
   ‘a beautiful curtain’

   Example 9-66. 

   un-as	cortina-s	hermos-as
   INDEF-PL.FEM	curtain	beautiful-PL.FEM
   ‘beautiful ...