ling 388: language and computers sandiway fong lecture 16: 10/20

LING 388: Language and Computers

Sandiway Fong

Lecture 16: 10/20

Last Time

• Japanese grammar– head-final:

• Subject Object Verb

– case particles: • -ga (nominative), -o (accusative)

– wh-in-situ (not fronted): • dare (who), nani (what)

– sentence-final Q-particle: • ka

– Examples:• Taroo-ga hon-o katta (declarative)• taroo-nom book-acc bought• Taroo-ga nani-o katta ka (object wh-question)• dare-ga hon-o katta ka (subject wh-question)

Last Time

• Japanese grammar– s(s(Y,Z)) --> np(Y,Q1), nomcase, vp(Z,Q2), sf(Q1,Q2).– vp(vp(Z,Y),Q) --> np(Z,Q), acccase, transitive(Y).– transitive(v(katta)) --> [katta].

– nomcase --> [ga].– acccase --> [o].

– np(np(taroo),notwh) --> [taroo].– np(np(hon),notwh) --> [hon].– np(np(dare),wh) --> [dare].– np(np(nani),wh) --> [nani].

– sf(wh,notwh) --> [ka].– sf(notwh,wh) --> [ka].– sf(notwh,notwh) --> [].– sf(wh,wh) --> [ka].

can both parse and generatewith thissimple grammar

Today’s Topics

– English Wh-Questions

Wh-Questions: English

• English– Declarative:

• John bought a book

– Wh-Question:• Who bought a book? (subject wh-phrase)• *John bought what? (only possible as an echo-question)• What did John buy? (object wh-phrase)

• Grammar Implementation– Subject wh-question:

• straightforward

– Object wh-question:• complex operation (irregular)

– object wh-phrase must be fronted– do-support (insertion of past tense form of “do”)– bought buy (untensed form)

Wh-Questions: Japanese



– Wh-Question:• Who bought a book? (subject wh-phrase)• *John bought what? (only possible as an echo-question)

• What did John buy? (object wh-phrase) • Japanese

– wh-in-situ: • meaning wh-phrase appears in same position as a regular noun phrase• easy to implement!

– Taroo-ga nani-o katta ka• nani: means what• ka: sentence-final question particle

– dare-ga hon-o katta ka• dare: means who

English Grammar

• Starting point:– assume the

grammar from the start of Lecture 13

– minus the troublesome left-recursive VP PP rule

s(s(Y,Z)) --> np(Y), vp(Z). np(np(Y)) --> pronoun(Y).np(np(D,N)) --> det(D,Number),

common_noun(N,Number).det(det(the),_) --> [the].det(det(a),sg) --> [a].common_noun(n(ball),sg) --> [ball].common_noun(n(man),sg) --> [man].common_noun(n(men),pl) --> [men].pronoun(i) --> [i].pronoun(we) --> [we].pronoun(me) --> [me]. vp(vp(Y)) --> unergative(Y). vp(vp(Y,Z)) --> transitive(Y,_), np(Z).vp(vp(A,V)) --> aux(A), transitive(V,en).unergative(v(ran)) --> [ran].transitive(v(hit),_) --> [hit].transitive(v(eat),root) --> [eat].transitive(v(eats),s) --> [eats].transitive(v(ate),ed) --> [ate].transitive(v(eaten),en) --> [eaten].aux(aux(was)) --> [was].

Wh-Questions: Step 1




• New words:– bought book john– who what

• Grammar rules:– transitive(v(ate),ed) --> [ate]. common_noun(n(ball),sg) --> [ball].– transitive(v(bought),ed) --> [bought].– common_noun(n(book),sg) --> [book].– np(np(N)) --> proper_noun(N).– proper_noun(john) --> [john].

• Need also to encode the wh feature– cf. Japanese grammar– np(np(nani),wh) --> [nani]. % what

Wh-Questions: Step 1• English

– Declarative:• John bought a book


• New words:– book john– who what

• Grammar rules:– common_noun(n(book),sg,notwh) --> [book].– common_noun(n(man),sg,notwh) --> [man].– common_noun(n(men),pl,notwh) --> [men].

– np(np(N),notwh) --> proper_noun(N). % e.g. john

– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].– pronoun(i,notwh) --> [i].– pronoun(we,notwh) --> [we].– pronoun(me,notwh) --> [me].

• Note:– what can also be a determiner, e.g. what man– [we’re not going to cover this case]





• New words: (book, who, what)– common_noun(n(book),sg,notwh) --> [book].– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].

• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – np(np(Y),Q) --> pronoun(Y,Q).– np(np(N),notwh) --> proper_noun(N).– np(np(D,N),Q) --> det(D,Number), common_noun(N,Number,Q).– vp(vp(Y,Z)) --> transitive(Y,_), np(Z,Q).

• Note:– got to pass wh feature information up to the noun phrase node level





• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – np(np(Y),Q) --> pronoun(Y,Q).– np(np(N),notwh) --> proper_noun(N).– np(np(D,N),Q) --> det(D,Number), common_noun(N,Number,Q).– vp(vp(Y,Z)) --> transitive(Y,_), np(Z,Q).– common_noun(n(book),sg,notwh) --> [book].– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].– proper_noun(john) --> [john].

• Declarative sentence:– ?- s(X,[john,bought,a,book],[]).– X = s(np(john),vp(v(bought),np(det(a),n(book))))





• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – np(np(Y),Q) --> pronoun(Y,Q).– np(np(N),notwh) --> proper_noun(N).– np(np(D,N),Q) --> det(D,Number), common_noun(N,Number,Q).– vp(vp(Y,Z)) --> transitive(Y,_), np(Z,Q).– common_noun(n(book),sg,notwh) --> [book].– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].– proper_noun(john) --> [john].

• Subject wh-question:– ?- s(X,[who,bought,a,book],[]).– X = s(np(who),vp(v(bought),np(det(a),n(book))))

• Note:– an in-situ analysis





• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – np(np(Y),Q) --> pronoun(Y,Q).– np(np(N),notwh) --> proper_noun(N).– np(np(D,N),Q) --> det(D,Number), common_noun(N,Number,Q).– vp(vp(Y,Z)) --> transitive(Y,_), np(Z,Q).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].

• Object wh-question:– ?- s(X,[john,bought,what],[]).– X = s(np(john),vp(v(bought),np(what)))

• How do we block this analysis?– By stipulating the value of Q– vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).





• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].

• Object wh-question:– ?- s(X,[what,did,john,buy],[]).

• We need to write rules for wh-object fronting– First, some rules for “do”– aux(aux(was)) --> [was].

– do(aux(did)) --> [did].– do(aux(do)) --> [do].– do(aux(does)) --> [does].

s

np vp

v

sbar

np

what

buy

john

aux

did

Wh-Questions: Step 2.1




• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].

• Object wh-question:– complex operation (irregular)


– Fronting– sbar(sbar(X,Y)) --> np(X,wh), s(Y).

s

np vp

v

sbar

np

what

buy

john

aux

did




– Wh-Question:• Who bought a book? (subject wh-

phrase)• *John bought what? (only possible as

an echo-question)• What did John buy? (object wh-

phrase)• Grammar Rules:

– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].


– object wh-phrase must be fronted

– do-support (insertion of past tense form of “do”)

– bought buy (untensed form)

– Do-support– sbar(sbar(X,A,Y)) --> np(X,wh), do(A), s(Y).

s

np vp

v

sbar

np

what

buy

john

aux

did

Wh-Questions: Step 2.3• English



phrase)• *John bought what? (only possible

as an echo-question)• What did John buy? (object wh-


– sbar(sbar(X,A,Y)) --> np(X,wh), do(A), s(Y).– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].



– Untensed main verb– transitive(v(bought),ed) --> [bought].– transitive(v(buy),root) --> [buy].

s

np vp

v

sbar

np

what

buy

john

aux

did







– sbar(sbar(X,A,Y)) --> np(X,wh), do(A), s(Y).– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].



– VP rule for missing (fronted) object– transitive(v(buy),root) --> [buy].– vp(vp(Y)) --> transitive(Y,root).

• Problem:– sbar rule allows any s node to be used– e.g. allows What did John buy a book

– How do we force our VP fronted rule to be used?

s

np vp

v

sbar

np

what

buy

john

aux

did







– sbar(sbar(X,A,Y)) --> np(X,wh), do(A), s(Y).– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– vp(vp(Y)) --> transitive(Y,root).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].



• How do we force our VP fronted rule to be used?– Pass information down the tree using the nonterminal name

• Modify rule– sbar(sbar(X,A,Y)) --> np(X,wh), do(A), s_objectwh(Y).

• Add new rule– s_objectwh(s(Y,Z)) --> np(Y,Q), vp_objectwh(Z).

• Modify rule– vp_objectwh(vp(Y)) --> transitive(Y,root).

s[objectwh]

np vp [objectwh]

v

sbar

np

what

buy

john

aux

did




– Wh-Question:• Who bought a book? (subject wh-phrase)• *John bought what? (only possible as an echo-

question)• What did John buy? (object wh-phrase)

• Grammar Rules:– s(s(Y,Z)) --> np(Y,Q), vp(Z). – vp(vp(Y,Z)) --> transitive(Y,_), np(Z,notwh).– pronoun(who,wh) --> [who].– pronoun(what,wh) --> [what].– sbar(sbar(X,A,Y)) --> np(X,wh), do(A),

s_objectwh(Y).– s_objectwh(s(Y,Z)) --> np(Y,Q), vp_objectwh(Z). – vp_objectwh(vp(Y)) --> transitive(Y,root).

• Query:– ?- sbar(X,[what,did,john,buy],[]).– X = sbar(np(what),aux(did),s(np(john),vp(v(buy))))

• Cleaning up:– sbar(S) --> s(S).

s[objectwh]

np vp [objectwh]

v

sbar

np

what

buy

john

aux

did

Next Time

• We’ll talk about machine translation

ling 388: language and computers sandiway fong lecture 16: 10/20

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