1.Introduction:describingandexplainingL2acquisitiona.WhatisSecondlanguageacquisition?Itsemergenceisnoaccident.ThishasbeenatimeoftheglobalvillageandtheWorldwideWeb.Asneverbefore,peoplehavehadtolearnasecondlanguage,notjustasapleasingpastime,butoftenasameansofobtaininganeducationofsecuringemployment.Secondcanrefertoanylanguagethatislearnedsubsequenttothemothertongue.Itcanrefertothethirdorfourthlanguage.Also,secondisnotintendedtocontrastwithforeign.soL2acquisitioncanbedefinedasthewayinwhichpeoplelearnalanguageotherthantheirmothertongue,insideoroutsideofaclassroom.SecondLanguageAcquisitionisthestudyofL2acquisition.b.WhatarethegoalofSLA?SomeapproachesforyoutosetaboutfindinghowthelearnersacquireanL2:1.askthelearnershowtheydidit.Thisapproachhasprovidedsomevaluableinsightsbutitislimitedinthatlearnersarenotawareoftheactuallearningprocesstheyengagedin2.collectingsamplesoflearnerlanguagethatlearnersproduceandanalysethemcarefully.Thesesamplesprovideevidenceofwhatthelearnersknowaboutthetargetlanguage.Ifthesamplesarecollectedatdifferentpointsintime,Itmaybepossibletofindouthowlearnersknowledgegraduallydevelops.inotherwords,whatwearetryingtoisdescribehowlearnerlanguagechangeovertime.c.thefocusofSLASLAhasnotfocusedonthesecommunicativeaspectsoflanguagedevelopment---howlearners’overallabilitytocommunicatedevelops,howtheybecomemorefluentintheiruseofanL2.butontheformalfeaturesoflanguagethatlinguistshavetraditionallyconcentratedon.-----pronunciation(howlearners’accentschangeovertime.)words---howlearnersbuilduptheirvocabulary;mostoften,thefocushasbeenonthegrammar---{thefocushasbeenthegrammaroftheL2}d.thegoalsofSLAOneofthegoalofSLAisthedescriptionofL2acquisition.Anotherisexplanation;identifyingtheexternalandinternalfactorsthataccountforwhylearnersacquireanL2inthewaytheydo.OneofthegoalofSLAaretodescribehowL2acquisitionproceedsandtoexplainthisprocessandwhysomelearnersseemtobebetterasitthanothers.e.Whataretheexternalandinternalfactors?Oneoftheexternalfactorsisthesocialmilieuinwhichlearningtakesplace.Socialconditionsinfluencetheopportunitieslearnershavetohearandspeakthelanguageandtheattitudesthattheydeveloptowardsit.Anotherexternalfactoristheinputthatlearnersreceive,thatis,thesampleoflanguagetowhichalearnerisexposed.Languagelearningcannotoccurwithoutsomeinput.L2acquisitioncanbeexplainedinpartbytheseexternalbutinternalfactorsalsoshouldbeconsidered.LearnerpossesscognitivemechanismswhichenabletoextractinformationaboutL2fromtheinput.L2learnerbringanenormousamountofknowledgetothetaskoflearninganL2.First,theycandrawonthemothertongue,Second,learnerspossessgeneralknowledgeaboutwhichcanhelpthemunderstandL2input.Finally,learnerspossesscommunicationstrategiesthathelpthemmakeeffectiveuseoftheirL2knowledge.Besides,ithasbeensuggestedthatpeoplevaryintheirlanguageaptitudef.twocasestudiesAcasestudyisadetailedstudyofalearner’sacquisitionofanL2,whichislongitudinal,involvingthecollectionofsamplesofthelearner’sspeechorwritingoveraperiodoftime.OneisofanadultlearnerlearningEnglishinsurroundingswhereitservesasameansofdailycommunicationandtheotheroftwochildrenlearningEnglishinaclassroom.ResearchSchmidtsays-----.Wes,anaturalisticlearner---wholearnsEnglishbylearningtocommunicateinit;hewasstillfarshortfornative–speakeraccuracy,buthediddevelopinotherways,eg,hisuseofformula,hecanidentifythefixedphrasesandpractisethemconsciously.ThishelphimdevelopfluencyinEnglish,Infact,weisasuccessfulcommunicator,askilledconversationalist.ResearcherRodEllissays----JandR.theinstructionthetwolearnersreceivedinvolvesbothformalinstructionandinformalinstruction.Thefocusistherequest.becauseEnglishisthemediumofcommunication,therearenumerousopportunitiesforthemtohearandperformrequests.thesimilaritiesbetweenJandR;1,bothwerecapableofsuccessfullyperformingsimplerequests.2,bothmanifesteddevelopmentintheirabilitytoperformrequests.3.manyoftheirrequestsseemedformulaicinnature.4,bothprogressedinmuchthesamewaydespitethefacttheyhaddifferentnativelanguages,however,theabilityislimitedinanumberofrespects.5,inshort,despiteampleopportunitytomasterrequests,bothwerestillfarshortofnative–likecompetenceattheendofthestudy.P11.Methodologicalissues1,whatneedstobedescribed2,whatitmeanstosaythatalearnerhasacquiredafeatureofthetargetlanguage.(Schmidtdefinesacquisitionintermsofwhetherthelearnermanifestspatternsoflanguageusethataremoreorlessthesameasnativespeakersofthetargetlanguage.However,thisconflateswhatlearnersknowwithwhattheycando.3,Whatdetermineswhetherlearnershaveacquiredaparticularfeature?4,itconcernslearner’soveruseoflinguisticformsintryingtomeasurewhetheracquisitionhastakenplaceP12,Issuesinthedescriptionoflearnerlanguage1,Whatistherolethattheformulasplay,notjustinenhancinglearner‘performancebutintheiracquisitionofanL22,hasthelearnersacquiredthelanguagesystematically?P12,twofindings1,Onefindingisthatlearnersmakeerrorsofdifferentkinds.Notonlyingrammaticalerrors,butsociolinguisticerrors2,Anotherfindingisthatlearnersacquireanumberofformulaicchunks,whichtheyusetoperformcommunicativefunctionsandwhichcontributet