Traditional ways of English learning such as memorizing a certain couple of words and reciting from the word list seem much easier than developing a useful vocabulary for L2 learners. However, learners complain that they have suffered from couples of difficulties as the words are easy to be forgotten. Compare with the ways of mechanical memorizing, it argues that pro?viding L2 learners with the development of useful lexical knowledge such as semantic information and morphological structure is more effective in the process of language acquisition. Moreover, developing a useful lexical knowledge is far more complicated for English learners.