1. 74.419 Artificial Intelligence 2005/06 Features, Gaps, Movement Questions and Passives

2. Features, Gaps, and Questions Features Questions Passives Gaps Movement

3. Sample Rule: (VP)  (V SUBCAT -np-vp:inf) (NP) (VP VFORM inf) Verb SUBCAT Feature Example: (VP)  (want SUBCAT -np-vp:inf) (class) (to end VFORM inf)

4. Sample Rule: (VP)  (V SUBCAT -np-pp:loc) (NP) (PP PFORM LOC) Prep. Phrases - PFORM Feature Example: (VP)  (put SUBCAT -np-pp:loc) (the tire) (on the cap PFORM loc)

5. Sample Rule: (VP)  (V SUBCAT -np-adjp) (NP) (ADJP) More Verb SUBCATs Example: (VP)  (held SUBCAT -np-adjp) (the cop) (responsible)

6. Auxiliaries - Some Features Modal Verb Complement Verb form 'base' e.g. did buy person, number e.g. I, you, he, we, they did Verb form 'past' e.g. did buy Complement Verb form 'past participle' e.g. have seen Verb form 'base' e.g. have paid

7. VP  (AUX COMPFORM base) (VP VFORM base) can see have to match (unification) VP  (AUX COMPFORM ?s) (VP VFORM ?s) general form VP  (AUX COMPFORM ing) (VP VFORM ing) is bringing VP  (AUX COMPFORM pastprt) (VP VFORM pastprt) has brought perfect, with past participle progressive

8. Questions

9. sentence / phrase: question Q, relative clause R Category (POS), here: PP-word (prepositional phrase) binary feature POSS: possessive type, here: time specification POS category, here: pronoun agreement, matches: 3 rd person singular or plural type of PP, here: location, motion spec. These characteristics give information about the type of the answer! QDET: used as determiner

10. Features: POSS, WH Rules for NP (noun phrase) inheritance of features Complement NP PRO question word (possessive pronoun): who, whose (POSS +), which, what QDET question (determiner): which (book), what (file) from rule 1 (POSS +): whose (book) PP question: where, when PP with NP question: in which store, in whose pockets

11. Parsing Question - Which dogs did he see? gap - NP missing

13. Passives

14. Active and Passive - Example gap - NP missing

15. VP  (AUX[be]) (VP[pastprt], +passgap) was moved VP[pastprt, +passgap]  V[_np, pastprt] moved move is normally V[_np] np is missing, thus +passgap Passives - Example The box was moved. VP[pastprt, +passgap]  (AUX[be]) (VP[pastprt], +passgap) features are inherited downwards / passed upwards from main verb, VP (move, moved)

16. Movement

20. Additional References  James Allen: Natural Language Understanding. Benjamin Cummings, 1995