【正确答案】正确答案：There are generally two types of factors that cause errors and mistakes in foreign language learning , one is inter-lingual, traced to the influence of the mother tongue, the other is intra-lingual, committed by language learners regardless of their L In second language learning, the learners attempt to transfer the features of their mother tongue to the second language. When the structures of the two languages are similar, we can get positive transfer; when the two languages are different in structures, negative transfer or interference occurs and results in errors. Not all errors are caused by the interference of the mother tongue. There are cases that the learner knows some rules of the target language but applies them in the wrong place. Errors of overgeneralization and hypercorrection belong to this type.