Syntactic Features

1. Syntactic Features Morphology, heads, gaps, etc. 600.465 - Intro to NLP - J. Eisner

2. 3 views of a context-free rule • generation (production): S  NP VP • parsing (comprehension): S  NP VP • verification (checking): S = NP VP • Today you should keep the third, declarative perspective in mind. • Each phrase has • an interface (S) saying where it can go • an implementation (NP VP) saying what’s in it • To let the parts of the tree coordinate more closely with one another, enrich the interfaces: S[features…] = NP[features…] VP[features…] 600.465 - Intro to NLP - J. Eisner

3. S NP VP Verb NP Examples Verb  thrills VP Verb NP S  NP VP A roller coaster thrills every teenager 600.465 - Intro to NLP - J. Eisner

4. 3 common ways to use features morphology of a single word: Verb[head=thrill, tense=present, num=sing, person=3,…]  thrills projectionof features up to a bigger phrase VP[head=, tense=, num=…]  V[head=, tense=, num=…] NP provided  is in the set TRANSITIVE-VERBS agreementbetween sister phrases: S[head=, tense=]  NP[num=,…] VP[head=, tense=, num=…] 600.465 - Intro to NLP - J. Eisner

5. num=sing num=sing num=sing thrills 3 Common Ways to Use Features Verb[head=thrill, tense=present, num=sing, person=3,…]  thrills VP[head=, tense=, num=…]  V[head=, tense=, num=…] NP S[head=, tense=]  NP[num=,…] VP[head=, tense=, num=…] S (generationperspective) NP VP Verb NP A roller coaster thrills every teenager 600.465 - Intro to NLP - J. Eisner

6. num=sing num=sing num=sing thrills 3 Common Ways to Use Features Verb[head=thrill, tense=present, num=sing, person=3,…]  thrills VP[head=, tense=, num=…]  V[head=, tense=, num=…] NP S[head=, tense=]  NP[num=,…] VP[head=, tense=, num=…] S (comprehensionperspective) NP VP Verb NP A roller coaster thrills every teenager 600.465 - Intro to NLP - J. Eisner

7. VP VP VP VP VP S NP Det The N V has N plan V been to V thrilling NP Otto NP Wanda V swallow

8. VP[n=1]  V[n=1] VP V[n=1]  has S NP[n=1] VP[n=1] S [num=1] [num=1] NP VP [num=1] [num=1] Det The N V has VP [num=1] N plan VP V been VP to VP V thrilling NP Otto NP[n=1]  Det N[n=1] N[n=1]  N[n=1] VP N[n=1]  plan NP Wanda V swallow

9. VP[n=]  V[n=] VP V[n=1]  has S NP[n=] VP[n=] S [num=1] [num=1] NP VP [num=1] [num=1] Det The N V has VP [num=1] N plan VP V been VP to VP V thrilling NP Otto NP[n=]  Det N[n=] N[n=]  N[n=] VP N[n=1]  plan NP Wanda V swallow

10. S NP VP [head=plan] Det The N V has VP [head=plan] N plan VP V been VP [head=plan] to VP V thrilling NP Otto NP Wanda V swallow NP[h=]  Det N[h=] N[h=]  N[h=] VP N[h=plan]  plan

11. S [head=thrill] NP VP [head=thrill] Det The N V has VP [head=thrill] N plan VP V been VP [head=swallow] [head=thrill] to VP V thrilling NP Otto [head=swallow] NP Wanda V swallow [head=swallow] [head=Wanda] [head=plan] [head=plan] [head=plan] [head=thrill] [head=Otto] NP[h=]  Det N[h=] N[h=]  N[h=] VP N[h=plan]  plan

12. S [head=thrill] NP VP [head=thrill] Det The N V has VP [head=thrill] N plan VP V been VP [head=swallow] [head=thrill] to VP V thrilling NP Otto [head=swallow] NP Wanda V swallow [head=swallow] [head=Wanda] • Why use heads? • Morphology(e.g.,word endings) • N[h=plan,n=1]  planN[h=plan,n=2+]  plans • N[h=thrill,tense=prog]  thrillingN[h=thrill,tense=past] thrilledN[h=go,tense=past] went [head=plan] [head=plan] [head=plan] [head=thrill] [head=Otto] NP[h=]  Det N[h=] N[h=]  N[h=] VP N[h=plan]  plan

13. S [head=thrill] NP VP [head=thrill] Det The N V has VP [head=thrill] N plan VP V been VP [head=swallow] [head=thrill] to VP V thrilling NP Otto [head=swallow] NP Wanda V swallow [head=swallow] [head=Wanda] • Why use heads? • Subcategorization (i.e., transitive vs. intransitive) • When is VP VNP ok?VP[h=]  V[h=] NPrestrict to   TRANSITIVE_VERBS • When is N NVP ok?N[h=]  N[h=] VPrestrict to   {plan, plot, hope,…} [head=plan] [head=plan] [head=plan] [head=thrill] [head=Otto] NP[h=]  Det N[h=] N[h=]  N[h=] VP N[h=plan]  plan

14. Equivalently: keep the template but make prob depend on , S [head=thrill] NP VP [head=thrill] Det The N V has VP [head=thrill] leave out, or low prob N plan VP V been VP [head=swallow] [head=thrill] to VP V thrilling NP Otto [head=swallow] NP Wanda V swallow [head=swallow] [head=Wanda] • Why use heads? • Selectional restrictions • VP[h=]  V[h=] NP • I.e., VP[h=]  V[h=] NP[h=] • Don’t fill template in all ways: VP[h=thrill]  V[h=thrill] NP[h=Otto] *VP[h=thrill]  V[h=thrill] NP[h=plan] [head=plan] [head=plan] [head=plan] [head=thrill] [head=Otto] NP[h=]  Det N[h=] N[h=]  N[h=] VP N[h=plan]  plan

15. Part of the English Tense System 600.465 - Intro to NLP - J. Eisner

16. VP V thrilling NP Otto S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=perf,head=thrill] V been [tense=prog, head=thrill] • Let’s distinguish the different kinds of VP by tense … [tense=prog,head=thrill] [head=Otto]

17. past past past V thrills NP Otto [tense=pres,head=thrill] [head=Otto] thrilled Past S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present tense

18. past eat past eat past V thrills NP Otto [tense=pres,head=thrill] [head=Otto] thrilled ate Past S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present tense

19. V thrills NP Otto [tense=pres,head=thrill] [head=Otto] S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present tense (again)

20. V has VP [tense=pres,head=have] [tense=perf,head=thrill] V thrilled NP Otto [tense=perf,head=thrill] [head=Otto] S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present perfect tense

21. V thrilled NP Otto [tense=perf,head=thrill] [head=Otto] S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] • Present perfect tense

22. eat eat eat eat V thrilled NP Otto [tense=perf,head=thrill] [head=Otto] eaten S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] • Present perfect tense not ate – why? • The yellow material makes it a perfect tense – what effects?

23. past past past had V thrilled NP Otto [tense=perf,head=thrill] [head=Otto] Past S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] • Present perfect tense

24. V thrills NP Otto [tense=pres,head=thrill] [head=Otto] S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present tense (again)

25. V is VP [tense=pres,head=be ] [tense=prog,head=thrill] V thrilling NP Otto [tense=prog,head=thrill] [head=Otto] S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present progressive tense

26. past past past was V thrilling NP Otto [tense=prog,head=thrill] [head=Otto] Past S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V is VP [tense=pres,head=be ] [tense=prog,head=thrill] • Present progressive tense

27. V has VP [tense=pres,head=have] [tense=perf,head=thrill] V thrilled NP Otto [tense=perf,head=thrill] [head=Otto] S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … • Present perfect tense (again)

28. VP V thrilling NP Otto S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] V been [tense=perf,head=be] [tense=prog, head=thrill] • Present perfect progressive tense [tense=prog,head=thrill] [head=Otto]

29. VP V thrilling NP Otto S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] V been [tense=perf,head=be] [tense=prog, head=thrill] • Present perfect progressive tense [tense=prog,head=thrill] [head=Otto]

30. past past past had VP Past V thrilling NP Otto S [tense=pres,head=thrill] NP VP [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] V been [tense=perf,head=be] [tense=prog, head=thrill] • Present perfect progressive tense [tense=prog,head=thrill] [head=Otto]

31. VP V would [tense=stem,head=thrill] [tense=cond,head=will] VP stem have V thrilling NP Otto S cond [tense=pres,head=thrill] NP VP cond [head=plan] [tense=pres,head=thrill] The plan … V has VP [tense=pres,head=have] [tense=perf,head=thrill] Conditional • Present perfect progressive tense V been [tense=perf,head=be] [tense=prog, head=thrill] [tense=prog,head=thrill] [head=Otto]

32. VP [tense=pres,head=thrill] V is [tense=pres,head=be] [tense=prog, head=thrill] [tense=prog,head=thrill] [head=Otto] VP [tense=perf,head=thrill] V been VP VP VP [tense=perf,head=be] [tense=prog, head=thrill] VP [tense=past,head=eat] V thrilling NP Otto NP Otto NP Otto V thrilling V eating [tense=prog,head=thrill] [head=Otto] V was [tense=past,head=be] [tense=prog, head=eat] [tense=prog,head=eat] [head=Otto] • So what pattern do all progressives follow?

33. VP [tense=pres,head=thrill] V is [tense=pres,head=be] [tense=prog, head=thrill] [tense=prog,head=thrill] [head=Otto]   VP VP VP  VP [tense=past,head=eat] V -ing NP Otto NP Otto NP Otto V thrilling V eating V was  [tense=past,head=be] [tense=prog, head=eat]  [tense=prog,head=eat] [head=Otto] • So what pattern do all progressives follow? VP [tense=perf,head=thrill] V been [tense=perf,head=be] [tense=prog, head=thrill] [tense=prog,head=thrill] [head=Otto]

34.   VP  V -ing NP Otto   Progressive: VP[tense=, head=, …]  V[tense=, stem=be…] VP[tense=prog, head= …] Perfect: VP[tense=, head=, …]  V[tense=, stem=have…] VP[tense=perf, head= …] Future or VP[tense=, head=, …]  V[tense=, stem=will…] conditional:VP[tense=stem, head= …] Infinitive: VP[tense=inf, head=, …]  toVP[tense=stem, head= …] Etc. As well as the “ordinary” rules: VP[tense=, head=, …]  V[tense=, head=, …] NP V[tense=past, head=have…]  had VP [tense=perf,head=thrill] V been [tense=perf,head=be] [tense=prog, head=thrill] [tense=prog,head=thrill] [head=Otto]

35. e Gaps (“deep” grammar!) • Pretend “kiss” is a pure transitive verb. • Is “the president kissed” grammatical? • If so, what type of phrase is it? • the sandwich that • I wonder what • What else has the president kissed Sally said the president kissed e Sally consumed the pickle with e Sally consumed e with the pickle 600.465 - Intro to NLP - J. Eisner

36. Gaps • Object gaps: • the sandwich that • I wonder what • What else has the president kissed e Sally said the president kissed e Sally consumed the pickle with e Sally consumed e with the pickle [how could you tell the difference?] • Subject gaps: • the sandwich that • I wonder what • What else has e kissed the president Sally said e kissed the president 600.465 - Intro to NLP - J. Eisner

37. e kissed the president Sally said e kissed the president Gaps • All gaps are really the same – a missing NP: • the sandwich that • I wonder what • What else has the president kissed e Sally said the president kissed e Sally consumed the pickle with e Sally consumed e with the pickle Phrases with missing NP: X[missing=NP] or just X/NP for short 600.465 - Intro to NLP - J. Eisner

38. VP V wonder [wh=yes] CP S [wh=yes] NP what /NP VP NP /NP what else could go here? e NP he VP/NP VP V was V was VP/NP NP him V kissing V kissing NP/NP what else could go here? VP V wonder CP [wh=yes] NP what [wh=yes] S/NP e

39. /NP S /NP VP /NP what else could go here? VP /NP V was VP/NP /NP e what else could go here? VP NP NP the sandwich [wh=no] CP V wonder CP [wh=yes] Comp that NP what [wh=yes] S/NP NP he NP he VP/NP V was NP V kissing V kissing NP/NP e

40. S VP what else could go here? VP V was VP/NP what else could go here? VP VP V believe [wh=no] CP V wonder CP [wh=yes] Comp that NP what [wh=yes] S/NP NP he NP he VP/NP V was NP the sandwich V kissing V kissing NP/NP e

41. i i S i VP i VP i i i NP To indicate what fills a gap, people sometimes “coindex” the gap and its filler. NP the sandwich /NP [wh=no] CP Comp that /NP • Each phrase has a unique index such as “i”. • In some theories, coindexation is used to help extract a meaning from the tree. • In other theories, it is just an aid to help you follow the example. /NP NP he /NP V was NP V kissing / NP e the moneyi I spend ei on the happinessj I hope to buy ej which violini is this sonataj easy to play ej on ei

42. has He gone • Lots of features(tense, number, person, gaps, vowels, commas, wh, etc., etc....) Help! • Sorry, that’s just how language is … • You know too much to write it down easily!