Context-Free Grammars

Question 1

Context-Free Grammar

Answer 1

The rules have a single variable on the left-hand side

Question 2

Probabilistic Context-Free-Grammar

Answer 2

Used to assign a probability to a parse tree

All the rules with the same left-hand side sum up to one

Question 3

Chomsky Normal Form

Answer 3

Convert a CFG to have exactly two non-terminal, or one terminal, symbol on the right-hand side

Question 4

Lexicon

Answer 4

The set of rules that make up a grammar

Question 5

Modeling Transitive Verbs

Answer 5

He hit me.

VPtrans -> Vtrans NP

Question 6

Modeling Intransitive Verbs

Answer 6

He sleeps.

VPintrans -> Vintrans

Question 7

Modeling Ditransitive Verbs

Answer 7

He gave me ten dollars.

VPditrans -> Vditrans NP NP

Question 8

Modeling Agreement

Answer 8

NPsing -> Det Nsing | Pron2sing | PN (proper noun)

NPplural -> Nplural | PronOther

Question 9

Modeling Relative Clauses

Answer 9

I saw the man who sleeps.
I saw the duck that John fed.

NP -> Det N RC (relative clause)
RC -> RP (relative pronoun) VPintrans | RP NP Vtrans | RP NP Vditrans NP