Abstract：Abstract: The previous researches on English vocabulary attrition respectively focused on external factors such as time and age or internal factors such as frequency and semantic class, and ignored the interaction of both. This research probed into the interaction of internal and external factors on attrition of English vocabulary. It adopted duration of non-learning as the external factor, word frequency and semantic as the internal factor and grammar judgment task as testing method to test attrition of English locative verbs of 40 non-English majors for successive six years. The results of the test are as follows: (1) A positive relation is found between verb attrition and duration of non-learning with the fifth year of non-learning as the key period of attrition. (2) Low frequency words bear heavier attrition than high frequency words do but effect of frequency perishes with the extension of non-learning years. (3) At the earlier period, the influence of semantic class is not so prominent. As the influence of frequency becomes weaker, semantic class turns into a more salient factor. (4) The interaction of internal and external factors casts a more conspicuous effect on attrition of vocabulary than those of time, frequency or semantic respectively. The results of this research indicate that the interaction of internal and external factors is an indispensable factor in vocabulary attrition even in language teaching.
Key Words: vocabulary attrition; duration of non-learning; frequency; semantic class; interaction of internal and external factors
