Parsing in English

Symbols

S = Sentence
NP = Noun Phrase
VP = Verb Phrase
PP = Preposition Phrase
AP = Adjective Phrase
Det = Determiner (the, a, those)
N = Noun (person, place or thing)
V = Verb (action word)
Prep = Preposition (in, on, between, under, in front, behind)
Qual = Qualifier (a lot, almost)
Adj = Adjective (describes noun, colours, tall, skinny)
Deg = Degree (very, extremely, barely)

Rules

Starting: S
Non-terminating: S, NP, VP, PP, AP
Terminating: Det, N, V, Adj, Prep, Qual, Deg

[] optional
* can have more than one

S -> NP VP
NP -> [Det] [AP]* N [PP]
VP -> [Qual] V [NP]* [PP]
PP -> [Qual] Prep [NP]
AP -> [Deg] Adj [Prep]

I ate.

Parse Tree:

Rules Trace:
= S
= <NP> <VP>
= <N> <V>
= I ate

The very large boat sank under the bridge.

Parse Tree:

Rules Trace:

= S
= <NP> <VP>
= <Det> <AP> <N> <V> <PP>
= Det <Deg> <Adj> N V <Prep> <NP>
= Det Deg Adj N V Prep <Det> <N>
= The very large boat sank under the bridge