ComputationalDiscourse

11-711AlgorithmsforNLP7 December2017

WhatIsDiscourse?

Discourse isthecoherentstructureoflanguageabovethelevelofsentencesorclauses.Adiscourseisacoherentstructuredgroupofsentences.

Whatmakesapassagecoherent?

Apracticalanswer:Ithasmeaningfulconnectionsbetweenitsutterances.

CoverofShel Silverstein’sWheretheSidewalkEnds (1974)

ApplicationsofComputationalDiscourse

• Automaticessaygrading• Automaticsummarization• Meetingunderstanding• Dialoguesystems

Kindsofdiscourseanalysis

• Discourse,monologue,dialogue,(conversation)

• Discourse(SLP Ch.21)vs.(Spoken)DialogueSystems(SLP Ch.24)

Discoursemechanismsvs.Coherenceofthought

• “Longer-range”analysis(discourse)vs.“deeper”analysis(realsemantics):– JohnboughtacarfromBill– BillsoldacartoJohn– Theywerebothhappywiththetransaction

Coherence,Cohesion• Coherencerelations:– JohnhidBill’scarkeys.Hewasdrunk.– JohnhidBill’scarkeys.Helikesspinach.

• Entity-basedcoherence(Centering)andlexicalcohesion:– Johnwenttothestoretobuyapiano– Hehadgonetothestoreformanyyears– Hewasexcitedthathecouldfinallyaffordapiano– Hearrivedjustasthestorewasclosingforthedayversus– Johnwenttothestoretobuyapiano– Itwasastorehehadgonetoformanyyears– Hewasexcitedthathecouldfinallyaffordapiano– ItwasclosingforthedayjustasJohnarrived

CohesioninNLP

DiscourseSegmentation

Goal:Givenrawtext,separateadocumentintoalinearsequenceofsubtopics.

Pyramidfromcommons.wikimedia.org

Discoursesegmentation:TextTiling

• Usingdipsincohesion tosegmenttext.

SupervisedDiscourseSegmentation

Ourinstances:placemarkersbetweensentences(orparagraphsorclauses)Ourlabels:yes(markerisadiscourseboundary)orno(markerisnotadiscourseboundary)Whatfeaturesshouldweuse?• Discoursemarkersorcuewords• Wordoverlapbefore/afterboundary• Numberofcoreferencechainsthatcrossboundary• Others?

CoherenceinNLP

CoherenceRelationsS1:JohnwenttothebanktodeposithispaycheckS2:HethentookabustoBill’scardealershipS3:HeneededtobuyacarS4:Thecompanyheworksfornowisn’tnearabuslineS5:HealsowantedtotalkwithBillabouttheirsoccerleague

SomeCoherenceRelationsHowcanwelabeltherelationshipsbetweenutterancesinadiscourse?Afewexamples:• Explanation:InferthatthestateoreventassertedbyS1 causesorcouldcausethestateoreventassertedbyS0.

• Occasion:AchangeofstatecanbeinferredfromtheassertionofS0,whosefinalstatecanbeinferredfromS1,orviceversa.

• Parallel:Inferp(a1,a2,…) fromtheassertionofS0andp(b1,b2,…) fromtheassertionofS1,whereaiandbi aresimilarforalli.

RSTCoherenceRelations

RSTformalrelationdefinition

• Relationname:Evidence• Constr onN:RnotbelievingNenoughforW• Constr onS:RbelievesS,orwould• Constr onN+S:R’sbelievingSwouldincreaseR’sbelievingN

• Effects:R’sbeliefofNisincreased

AutomaticCoherenceAssignment

Givenasequenceofsentencesorclauses,wewanttoautomatically:• determinecoherencerelationsbetweenthem(coherencerelationassignment)

• extractatreeorgraphrepresentinganentirediscourse(discourseparsing)

AutomaticCoherenceAssignment

Verydifficult.Oneexistingapproachistousecuephrases.

JohnhidBill’scarkeysbecause hewasdrunk.Thescarecrowcametoaskforabrain.Similarly,the

tinmanwantsaheart.1) Identifycuephrasesinthetext.2) Segmentthetextintodiscoursesegments.3) Classifytherelationshipbetweeneach

consecutivediscoursesegment.

AutomaticCoherenceAssignment

• “Discourseparsing”?• Usecuephrases/discoursemarkers– although,but,because,yet,with,…– butoftenimplicit,asincarkeyexample

• Useabduction,defeasibleinference– Allmenaremortal–Maxwasmortal–MaybeMaxwasaman

• Thecitydeniedthedemonstratorsapermitbecausethey(feared/advocated)violence

Pragmatics

Pragmatics

Pragmaticsisabranchoflinguisticsdealingwithlanguageuseincontext.

Whenadiplomatsaysyes,hemeans‘perhaps’;Whenhesaysperhaps,hemeans‘no’;Whenhesaysno,heisnotadiplomat.

(VariouslyattributedtoVoltaire,H.L.Mencken,andCarlJung)

Quotefromhttp://plato.stanford.edu/entries/pragmatics/

InContext?

• Socialcontext– Socialidentities,relationships,andsetting

• Physicalcontext–Where?Whatobjectsarepresent?Whatactions?

• Linguisticcontext– Conversationhistory

• Otherformsofcontext– Sharedknowledge,etc.

SpeechActs

(Direct) Speech Acts

• Mood of a sentence indicates relation between speaker and the concept (proposition) defined by the LF

• There can be operators that represent these relations:

• ASSERT: the proposition is proposed as a fact

• YN-QUERY: the truth of the proposition is queried

• COMMAND: the proposition describes a requested action

• WH-QUERY: the proposition describes an object to be identified

Indirect Speech Acts

• Can you pass the salt?

• It’s warm in here.

Austin,Howtodothingswithwords

• Inadditiontojustsayingthings,sentencesperformactions.

• Whenthesesentencesareuttered,theimportantthingisnottheirtruthvalue,butthefelicitousness oftheaction (e.g.,doyouhavetheauthority todoit):– InamethisshiptheQueenElizabeth.– Itakethismantobemyhusband.– Ibequeaththiswatchtomybrother.– Ideclarewar.

• http://en.wikipedia.org/wiki/J._L._Austin

Performative sentences• Youcantellwhethersentencesareperformativebyadding“hereby”:– IherebynamethisshiptheQueenElizabeth.– I herebytakethismantobemyhusband.– Iherebybequeaththiswatchtomybrother.– Iherebydeclarewar.

• Non-performative sentencesdonotsoundgoodwithhereby:– Birdsherebysing.– ThereisherebyfightinginSyria.

Austincontinued

• Locution:saysomewords• Illocution:anactionperformedin sayingwords– Ask,promise,command

• Perlocution:anactionperformedby sayingwords,probablytheeffectthatanillocutionhasonthelistener.– Persuade,convince,scare,elicitananswer,etc.

Searle’sspeechactsSearle(1975) hassetupthefollowingclassificationofillocutionaryspeechacts:

• assertives =speechactsthatcommitaspeakertothetruthoftheexpressed proposition,e.g.recitinga creed

• directives =speechactsthataretocausethehearertotakeaparticularaction,e.g.requests,commandsandadvice

• commissives =speechactsthatcommitaspeakertosomefutureaction,e.g.promisesandoaths

• expressives =speechactsthatexpressthespeaker'sattitudesandemotionstowardstheproposition,e.g.congratulations,excusesandthanks

• declarations =speechactsthatchangetherealityinaccordwiththepropositionofthedeclaration,e.g.baptisms,pronouncingsomeoneguiltyorpronouncingsomeonehusbandandwife

• http://en.wikipedia.org/wiki/Speech_act

Searleexample

• Indirectspeechacts:– Canyoupassthesalt?• Hastheformofaquestion,buttheeffectofadirective.

SpeechActsinNLP

Task-OrientedDialogue

• Makingtravelreservations(flight,hotelroom,etc.)

• Schedulingameeting.• Taskorienteddialoguesthatarefrequentlydonewithcomputers:– Findingoutwhenthenextbusis.–Makingapaymentoverthephone.

Waystoaskforaroom

• I’dliketomakeareservation• I’mcallingtomakeareservation• Doyouhaveavacancyon...• CanIreservearoom• Isitpossibletoreservearoom

Domain-specificspeechacts:travelscheduling(NESPOLE!Project)

(aprimitiveversionofthespeechtranslation)

• 61.2.3olangITAlangITAPrvIRST“Telefonoperprenotaredellestanzeperquattro colleghi”

• 61.2.3olang ITAlang ENGPrv IRST“Iamcallingtobooksomeroomsforfourcolleagues”

• 61.2.3IFPrv IRSTc:request-action+reservation+room (room-spec=(room,quantity=some),for-whom=(colleague,quantity=4))

• comments:dial-oo5-spkB-roca0-02-3

Task-orienteddialogueactsrelatedtonegotiation

• Suggest– Irecommendthishotel.

• Offer– Icansendsomebrochures.– HowaboutifIsendsomebrochures.

• Accept– Sure.Thatsoundsfine.

• Reject– No.Idon’tlikethatone.

ExamplesofSpeechActinventoriesusedinlanguagetechnologies

• Theseinventoriesareactuallyannotationschemes.

• Theyareusedforcorpusannotation.• Thecorpusannotationisusedforautomatedlearning.

• Theyarehighlydevelopedandcheckedforintercoder agreement.– Butstilltakealongtimetolearn.

Examplesoftask-orientedspeechacts• Identifyself:

– ThisisLori– MynameisLori– I’mLori– Lorihere

• Soundcheck:Canyouhearme?• Metadialogueact:Thereisaproblem.• Greet:Hello.• Request-information:–Whereareyougoing.– Tellmewhereyouaregoing.

Examplesoftask-orientedspeechacts• Backchannel:– Soundsyoumaketoindicatethatyouarestilllistening– ok,m-hm

• Apologize/replytoapology• Thank/replytothanks• Requestverification/Verify– Sothat’s2:00?Yes.2:00.

• Resumetopic– Backtotheaccommodations….

• Answerayes/noquestion:yes,no.

DAMSLDialogueActMarkupinSeveralLayers

• Fortask-orientedornon-task-orienteddialogue.• However,muchofthedevelopmentwasrelatedtotask-

orienteddialogues:– Trainscorpus– Maptask corpus– Meetingschedulingcorpus

• Althoughithasbeenusedfornon-task-orienteddialogue:– Switchboardcorpus(JHUworkshop1997)– SpanishCallHome corpus(ClarityProject,Waibel,Levin,Lavie)– Textmessagecorpus(Proprietaryproject,Levin,Rudnicky,Tenny)

• Whatarethelayers?– Forwardfunction:offer,ask– Backwardfunction:backchannel,accept,reject

Forwardlookingfunctions• Statement

– Assert– Reassert– Other-statement

• Influencing-addressee-future-action– Open-option– Action-directive

• Info-request• Committing-speaker-future-action

– Offer– Commit

• ConventionalOpeningClosing• Explicit-performative• Exclamation• Other-forward-function

Backwardlookingfunctions• Agreement

– Accept– Acceptpart– Maybe– Rejectpart– Reject– Hold

• Understanding– Signalnon-understanding– Signalunderstanding

• Acknowledge• Repeat• Complete

– Correctmisspeaking• Answer

Now,afamousbadidea(linkedtoagoodidea)

Grice’sMaxims

• Whydothesemakesense?– Areyou21?– Yes.I’m25.

– I’mhungry.– I’llgetmykeys.

–WherecanIgetcigarettes?– Thereisagasstationacrossthestreet.

Grice’sMaxims• Whyarethesestrange?

– (Thestudentsareallgirls.)– Somestudentsaregirls.

– (Therearesevennon-stopflights.)– Therearethreenon-stopflights.

• Jurafsky andMartin,page820

– (Inaletterofrecommendationforajob)– Istronglypraisetheapplicant’simpeccablehandwriting.

Grice’sCooperativePrinciple

• “Makeyourcontributionsuchasitisrequired,atthestageatwhichitoccurs,bytheacceptedpurposeordirectionofthetalkexchangeinwhichyouareengaged.”

• TheCooperativePrincipleisgoodandright.

• Ontheotherhand,wehavetheMaxims:

Grice’sactualMaxims• MaximofQuality

– Trytosaysomethingtrue;donotsaysomethingfalseorforwhichyoulackevidence.

• MaximofQuantity– Sayasmuchasisrequiredtobeinformative– Donotmakeyourcontributionmoreinformativethanrequired

• MaximofRelevance– BeRelevant

• MaximofManner– Beperspicuous– Avoidambigtuity– Bebrief– Beorderly

Flouting theCooperativePrinciple

• “Nicethrow.”(saidafterterriblethrow)

• “Ifyourunalittleslower,you’llnevercatchuptotheball.”(duringmediocrepursuitofball)

• Youcan indeedimplysomethingbyclearlyviolatingtheprinciple.– TheMaximsstill suck.

Flout ≠Flaunt

• Flout:openlydisregard(arule,laworconvention).

• Flaunt:display(something)ostentatiously,especiallyinordertoprovokeenvyoradmirationortoshowdefiance.– Source:Google

MypaperontheMaxims

• Grice'sMaxims:"DotheRightThing" byRobertE.Frederking.ArguesthattheGricean maximsaretoovaguetobeusefulfornaturallanguageprocessing.[fromWikipediaarticle]

• “Iusedtothinkyouwereaniceguy.”– Actualquotefromagradstudent,afterreadingthepaper

Referenceresolution

ReferenceResolution:example• VictoriaChen,CFOofMegabucksBankingCorpsince2004,sawherpay jump20%,to$1.3million,asthe37-year-oldalsobecametheDenver-basedcompany’spresident.Ithasbeentenyearssinceshe cametoMegabucks fromrivalLotsaloot.

• Shouldgive4coreference chains:– {VictoriaChen,CFOofMegabucksBankingCorpsince2004,her,the37-year-old,theDenver-basedcompany’spresident,she}

– {MegabucksBankingCorp,theDenver-basedcompany,Megabucks}

– {herpay}– {Lotsaloot}.

CoreferenceResolution

Marypickeduptheball.Shethrewittome.

Referenceresolution

Marypickeduptheball.Shethrewittome.

(Co)ReferenceResolution

• Determiningthereferentofareferringexpression.Anaphora,antecedentscorefer.

• 1961FordFalcon:it,this,that,thiscar,thecar,theFord,theFalcon,myfriend’scar,…

• Coreference chainsarepartofcohesion• Note:otherkindsofreferents:– AccordingtoDoug,SuejustboughttheFordFalcon• Butthat turnedouttobealie• Butthat wasfalse• That struckmeasafunnywaytodescribethesituation• That causedafinancialproblemforSue

TypesofReferringExpressions• IndefiniteNPs:a/an,some,this,ornothing– newentities;specific/non-specificambiguity

• DefiniteNPs:usuallythe– anentityidentifiablebythehearer

• Pronouns:he,them,it,etc.Alsocataphora.– strongconstraintsontheiruse– canbebound:Everystudentimprovedhisgrades

• Demonstratives:this,that• Names:construedtobeunique,buttheyaren’t– IsthattheBobinLTIortheBobintheLaneCenter?

Informationstructure:given/new

• Wherearemyshoes?Yourshoes areinthecloset• What’sinthecloset?– ??Yourshoes areinthecloset.– Yourshoes areinthecloset.

• Definiteness/pronoun,length,positioninS

Complications

• Inferrables:Somecar.…adoor…theengine…• Generics:AtCMUyouhavetoworkhard.• Pleonastic/clefts/extraposition:– Itisraining.Itwasmewhocalled.Itwasgoodthat…

ReferenceResolution

Goal:determinewhatentitiesarereferredtobywhichlinguisticexpressions.

Thediscoursemodelcontainsoureligiblesetofreferents.

Pronouns:FiltersandPreferences

Pronounreferenceresolution:filters

• Agreementinnumber,person,gender• Pittsburghdialect:yinz=youse=y’all• UKdialect:Newcastleareaphysicalteam.

– Lcanhave>2numbers,>3persons,or>3genders• Bindingtheory:reflexive required/prohibited:– JohnboughthimselfanewFord.[himself=John]– JohnboughthimanewFord.[him!=John]– JohnsaidthatBillboughthimanewFord.[him!=Bill]– JsaidthatBboughthimselfanewF.[himself=Bill]– HesaidthatheboughtJanewFord.[both he!=J]

Pronounreferenceresolution:preferences• Recency:preferenceformostrecentreferent• GrammaticalRole:subj>obj>others– BillywenttothebarwithJim.Heorderedrum.

• Repeatedmention:Billyhadbeendrinkingfordays.Hewenttothebaragaintoday.Jimwentwithhim.Heorderedrum.

• Parallelism:JohnwentwithJimtoonebar.Billwentwithhimtoanother.

• Verbsemantics:Johnphoned/criticizedBill.Helostthelaptop.

• Selectional restrictions:Johnparkedhiscarinthegarageafterdrivingitaroundforhours.

Threecomputationalapproachestopronouns

PNref.res.1:HobbsAlgorithm

• Algorithmforwalkingthroughparsesofcurrentandprecedingsentences

• Simple,oftenusedasbaseline

• Requiresparser,morphgenderandnumber– plusheadrulesandWordNet forNPgender

• Implementsbindingtheory,recency,andgrammaticalrolepreferences

PNref.res.2:Centeringtheory• Claim:asingleentityis“centered”ineachS• Backward-lookingcenter,Forward-lookingcenters• Cb =mosthighlyrankedCf usedfromprev.S• Rank:Subj>ExistPredNom>Obj>IndObj-Obl>DemAdvPP

• Definedtransitions:(Cp isfrontofCf list)

Rule1:IfanyCf usedasPron+1,thenCb(n+1) mustbeProtooRule2:Rank:Continue>Retain>Smooth>Rough

U1:JohnsawaFordatthedealershipCb:NILCf:John,Ford,dealership

U2:HeshowedittoBob[Bob!=he]He=John,it={Ford,dealership}Cb=John• (it->Ford)=>Cf:{John,Ford,Bob}=>CONTINUE[tie-winner]• (it->dealership)=>Cf:{John,dealer,Bob}=>CONTINUE

U3:Heboughtit[dealership isnowunavailable]He={John,Bob},it=Ford• (he->John)=>Cb=John,Cf={John,Ford}=>CONTINUE[Win]• (he->Bob)=>Cb=Bob,Cf={Bob,Ford}=>SMOOTH

Centeringtheory

• SamerequirementsasHobbs• ImplementsGrammaticalRole,Recency,andRepeatedMention

• Canmakemistakes:– Bobopenedanewdealershiplastweek– JohntookalookattheFordsinhislot[Cb=Bob]– Heendedupbuyingone• He=Bob=>CONTINUE,He=John=>SMOOTH

PNref.res.3:Log-linearmodel

• Supervised:hand-labelled coref corpus• Rule-basedfilteringofnon-referentialpronouns• Features,valuesforHe inU3:

GeneralReferenceResolution

GeneralCoreference Resolution• VictoriaChen,CFOofMegabucksBankingCorpsince2004,sawherpay jump20%,to$1.3million,asthe37-year-oldalsobecametheDenver-basedcompany’spresident.Ithasbeentenyearssinceshe cametoMegabucks fromrivalLotsaloot.

• Shouldgive4coreference chains:– {VictoriaChen,CFOofMegabucksBankingCorpsince2004,her,the37-year-old,theDenver-basedcompany’spresident,she}

– {MegabucksBankingCorp,theDenver-basedcompany,Megabucks}

– {herpay}– {Lotsaloot}.

President Park Geun-hye of South Korea ordered the country’s military on Monday to deliver a strong and immediate response to any North Korean provocation, the latest turn in a war of words that has become a test of resolve for the relatively unproven leaders in both the North and South.“I consider the current North Korean threats very serious,” Ms. Park told the South’s generals. “If the North attempts any provocation against our people and country, you must respond strongly at the first contact with them without any political consideration.“As top commander of the military, I trust your judgment in the face of North Korea’s unexpected surprise provocation,” she added.Since Kim Jong-un took power after the death of his father, Kim Jong-il, in late 2011, the North has taken a series of provocative steps and amplified threats against Washington and Seoul to much louder and more menacing levels. The North has launched a three-stage rocket, tested a nuclear device and threatened to hit major American cities with nuclear-armed ballistic missiles. And Mr. Kim has declared that the Korean Peninsula has reverted to a “state of war.”

President Park Geun-hye of South Korea ordered the country’s military on Monday to deliver a strong and immediate response to any North Korean provocation, the latest turn in a war of words that has become a test of resolve for the relatively unproven leaders in both the North and South.“I consider the current North Korean threats very serious,” Ms. Park told the South’s generals. “If the North attempts any provocation against our people and country, you must respond strongly at the first contact with them without any political consideration.“As top commander of the military, I trust your judgment in the face of North Korea’s unexpected surprise provocation,” she added.Since Kim Jong-un took power after the death of his father, Kim Jong-il, in late 2011, the North has taken a series of provocative steps and amplified threats against Washington and Seoul to much louder and more menacing levels. The North has launched a three-stage rocket, tested a nuclear device and threatened to hit major American cities with nuclear-armed ballistic missiles. And Mr. Kim has declared that the Korean Peninsula has reverted to a “state of war.”

President Park Geun-hye of South Korea ordered the country’s military on Monday to deliver a strong and immediate response to any North Korean provocation, the latest turn in a war of words that has become a test of resolve for the relatively unproven leaders in both the North and South.“I consider the current North Korean threats very serious,” Ms. Park told the South’s generals. “If the North attempts any provocation against our people and country, you must respond strongly at the first contact with them without any political consideration.“As top commander of the military, I trust your judgment in the face of North Korea’s unexpected surprise provocation,” she added.Since Kim Jong-un took power after the death of his father, Kim Jong-il, in late 2011, the North has taken a series of provocative steps and amplified threats against Washington and Seoul to much louder and more menacing levels. The North has launched a three-stage rocket, tested a nuclear device and threatened to hit major American cities with nuclear-armed ballistic missiles. And Mr. Kim has declared that the Korean Peninsula has reverted to a “state of war.”

President Park Geun-hye of South Korea ordered the country’s military on Monday to deliver a strong and immediate response to any North Korean provocation, the latest turn in a war of words that has become a test of resolve for the relatively unproven leaders in both the North and South.“I consider the current North Korean threats very serious,” Ms. Park told the South’s generals. “If the North attempts any provocation against our people and country, you must respond strongly at the first contact with them without any political consideration.“As top commander of the military, I trust your judgment in the face of North Korea’s unexpected surprise provocation,” she added.Since Kim Jong-un took power after the death of his father, Kim Jong-il, in late 2011, the North has taken a series of provocative steps and amplified threats against Washington and Seoul to much louder and more menacing levels. The North has launched a three-stage rocket, tested a nuclear device and threatened to hit major American cities with nuclear-armed ballistic missiles. And Mr. Kim has declared that the Korean Peninsula has reverted to a “state of war.”

President Park Geun-hye of South Korea ordered the country’s military on Monday to deliver a strong and immediate response to any North Korean provocation, the latest turn in a war of words that has become a test of resolve for the relatively unproven leaders in both the North and South.“I consider the current North Korean threats very serious,” Ms. Park told the South’s generals. “If the North attempts any provocation against our people and country, you must respond strongly at the first contact with them without any political consideration.“As top commander of the military, I trust your judgment in the face of North Korea’s unexpected surprise provocation,” she added.Since Kim Jong-un took power after the death of his father, Kim Jong-il, in late 2011, the North has taken a series of provocative steps and amplified threats against Washington and Seoul to much louder and more menacing levels. The North has launched a three-stage rocket, tested a nuclear device and threatened to hit major American cities with nuclear-armed ballistic missiles. And Mr. Kim has declared that the Korean Peninsula has reverted to a “state of war.”

High-LevelRecipeforCoreferenceResolution

1. ParsethetextandidentifyNPs;then2. ForeverypairofNPs,carryoutbinary

classification:coreferential ornot?3. Collecttheresultsintocoreferential chains

Whatdoweneed?-Achoiceofclassifier-Lotsoflabeleddata-Features

Features?• EditdistancebetweenthetwoNPs• ArethetwoNPsthesameNERtype?• Appositivesyntax– “AlanShepherd,thefirstAmericanastronaut…”

• Proper/definite/indefinite/pronoun• Gender• Number• Distanceinsentences• NumberofNPsbetween• Grammaticalrole• etc.

MoreCoreference Resolution

• Combinebest:ENCORE(BoLinetal2010)• MLforCross-DocCoref (Rushin Shahetal2011)

EntityLinking

Apple updateditsinvestorrelationspagetodaytonotethatitwillannounceitsearningsforthesecondfiscalquarter(firstcalendarquarter)of2015onMonday,April27.

Newstextfromhttp://www.macrumors.com/2015/03/30/apple-to-announce-q2-2015-earnings-on-april-27/

OneApproachtoEntityLinking

Usesupervisedlearning:Trainonknownreferencestoeachentity.Usefeaturesfromcontext(bagofwords,syntax,etc.).

Questions?