Constructing a grammar and parsing a sentence based on Natural Language Processing Concept

Natural Language Processing (NLP): means processing the Natual Human language e.g. English, Bangla etc in concern so that it can be represented in a machine-readable format. 

And we all know that language consists of grammar.

Example:

Sentence: The fact that earth moves around the sun astonished him.

           

Grammar:

                                S ---> NP VP

                                VP ---> V (P) NP

                                P ---> Preposition

                                NP ---> D N (S’)

                                NP ---> N

                                S’ ---> Comp S

                Lexicon:

                D ---> the | a | an

                Preposition ---> around

                Comp ---> that

                N ---> fact | earth | sun | him

                V ---> move | moves | astonish | astonished

               

Level-Bracket the syntactic tree:

                

[S [NP [D The D] [N fact N] [S’ [Comp that Comp] [S [NP [N earth N] NP] [VP [V moves V] [P [Preposition around Preposition] P] [NP [D the D] [N sun N] NP] VP] S] S’] NP] [VP [V astonished V] [NP [N him N] NP] VP] S]