2。 Literature Review
2。1 Receptive and Productive Vocabulary
Researchers generally agree that there is a difference between receptive and productive vocabulary。 In other words, a great distinction exists between vocabularies used for comprehension and vocabulary used for production。 According to Haycraft (1978), receptive words vocabulary is defined as words can be recognized and understood but cannot be produced correctly when they occur in a text, while productive vocabulary is defined as words that learner understands and can produce and use correctly in speaking and writing。
Nation points out that receptive vocabulary involves the perception of word form while listing or reading or retrieving its meaning。 Productive vocabulary involves expressing a meaning through speaking or writing and retrieving and producing the appropriate spoken or written word form (Nation, 2011a, pp。 24-25)。 Under the guidance of this point of view, eight kinds of vocabulary knowledge are advanced。 In order to illustrate each type of vocabulary knowledge, nation designed an “instructional manual”