Chapter 1:
Easy, just using some API.
Important API : FreqDist().
Some natural language understanding technologies : Word Sense Disambiguation, Pronoun Resolution, Generating Languge Output, Machcine Translation, Spoken Dialogue Systems, Textual Entailment.
Chapter 2:
Learn to access text corpora and lexical resource.
Important API : ConditionalFreqDist(), words(), sents(),raw().
Corpora:
To get lexical resource :
WordNet (semantic oriented, large number of info about words)
WordList
StopWords
To get a collection of text(some with category):
Gutenberg
Brown
Web and Chat Text