In the researches of second language acquisition(SLA)field,many aspects have been studied to explain and analyze leers interlanguage.This study based on the writing materials of two non-native leers of English tries to do find and discuss some features of SLA,especially Interlanguage.The point it focuses on is tense-aspect,to be more specific,the past tense.Some errors will be analyzed and classified with some modest explanations and solutions of these errors in leer language.