文档介绍：,publications,,wecouldsaythatbetween1920sand1970s,themainstreamoflanguageacquisitionresearchisthefocusonlanguagepedagogy;from1980son,themaintrendoflanguageacquisition,bothL1AandL2A,isthestudyofvariouslanguagetheories,,fromtheoriestotheories;ThisgroupincludesNoamChomsky,LydiaWhite,JuliaRogers,,fromtheoriestopractice,andincludesVivianCook,RodEllis,PatsyLightbown,MichaelLong,SusanGass,TeresaPica,,wealsofindthatsomeapproachesaredirectlyapplicabletothecalssroom,,,itwasstronglybelievedthatpracticemakesperfect;Secondly,teachersneededtofocustheirteachingonstructuresbelievedtobedifficult,’errors:trsnsfer,overgeneralizationandmarkedness;he