Even if we think only the first step of the process of vocabulary acquisition (knowing the meaning and the form of a word and linking them together), the number of words required for enough understanding of text-based reading or speech is very high. It is barely practicable just to pick up an enough number of words from reading or communication tasks without specific focus on vocabulary acquisition. Many researchers such as Judd (1978), Nation (2001), and Schmitt (2008) argue for a proactive approach of vocabulary expansion which requires offerings from four stakeholders: researchers, textbook writers, teachers, and students. Strong and active offerings from all members of the learning partnership is required. If students do not become active learners, they are unlikely to acquire a reasonable vocabulary size, no matter how good their textbooks or the level of instruction can be.
Nyikos & Fan, 2007) recommend that the fact that the vocabulary needs of learners often outshine the ability of learner to acquire a large number of new words has encouraged research into how vocabulary-learning strategies can assist learners. Many studies of the vocabulary-learning strategies used by L2 learners have described that learners differ in the range of strategies they use and in the usefulness with what they apply those strategies in their learning (Gu & Johnson 1996; Lawson & Hogben 1996; Schmitt 1997).
There are many studies researching the effectiveness of particular vocabulary learning strategies, such as memory-based strategies, inferencing strategies, incidental vocabulary learning from reading, or consulting reference sources. O’Malley & Chamot (1990) say that many studies show that the sensible and matched use of such learning strategies is connected with language achievement and proficiency. However, most researches have focused on specific vocabulary learning strategies used by learners of English as a second or a foreign language.
In this study, the samples are young learners of about 9-10 years old students and they are unable to choose vocabulary learning strategies, so the teacher has to choose the suitable ways for them to learn fifty vocabulary words which state in each lesson plan.