The findings from Kung’s (2004) research pointed out that EFL teachers can facilitate students to learn vocabulary more effectively through strategies teaching.
For example, in this study, it was found that students’ knowledge of phonics and K.K. phonetic symbols was a critical factor affecting the students’ speed to memorize
English vocabulary. Teachers should provide ways to help them obtain phonetic knowledge or encourage them to take good use of dictionary to enhance word knowledge. In addition, teaching vocabulary learning strategies can help students increase their vocabulary, such as using word parts and using the dictionary (Graves,
2006).Consequently, it is important to gain information on the vocabulary learning strategies learners actually use to facilitate their vocabulary acquisition as well as how helpful learners believe these learning strategies to be (Wu, 2005). Besides, teachers should inspire them to use some useful strategies frequently. Teachers should play an important role to help the learners to explore effective vocabulary learning strategies and methods by teaching students strategies in different ways. Oxford and Crookal
(1990) stated that strategies can be employed through simulations, games, and other active exercises or activities. Then it can make students have more opportunities to practice with a range of contexts and it can develop independent learners in vocabulary learning (Oxford, 1990). Most important of all, strategies should aid both in discovering the meaning of a new word and in consolidating a word once it has been encountered. Thus, after strategies are learned, learner should approach independent learning of vocabulary by using a combination of extensive reading and self-study strategies (Laufer, 1990). In a nutshell, it is best to teach learners strategies for dealing with these words than to teach the words themselves (Nation, 1990).
However, there are many factors influencing strategy use: degree of awareness, stage of learning, task requirements, teacher expectations, age sex, nationality/ethnicity,

general learning style, personality traits, motivation level, and purpose for learning the language (Oxford, 1990). Moreover, when considering which vocabulary strategies to suggest to our students, we need to consider the overall learning context (Schmitt,
2000). Teachers need to depend on a number of variables to decide which learning strategies can be taught and used, including the proficiency level, L1 and culture of students, their motivation and purpose for learning the L2, the task and text being used, and the nature of the L2 itself.