4 Occasionally makes grammatical errors but doesn't affect the meaning 3 Often makes grammatical errors that affect meaning 2 Many grammatical errors hinder meaning and often rearrange sentences 1 The grammatical errors were so severe that they were hard to understand Vocabulary 5 Use vocabulary and expressions like native speakers 4 Sometimes using inappropriate vocabulary 3 Often using inappropriate vocabulary, explanations are limited due to limited vocabulary 2 Using the wrong词汇和有限的词汇使难以理解1个词汇是如此有限，以至于说明是不可能的流利5，像母语4的流利4似乎受到语言问题的略微损害。了解大部分说的话，尽管讲话有些重复2，但很难遵循所讲的话。1甚至不明白描述一个简单的对象（David P. Haris，2007）