The Important of Vocabulary in English Learning Skill
Vocabulary is very important in producing a language. Therefore, having sufficient amount of vocabulary as well as mastering the use of vocabulary is also important in order to be able to use the language well. English teachers are strongly recommended to provide certain numbers of vocabulary for certain length of time in order the students to have sufficient numbers of vocabulary. David Nunan has an argument: Vocabulary was the easier aspect of a second language to learn and that is hardly equipped formal attention in the classroom.
The more one’s vocabulary is developed, the easier it is to add new words. To make sure the importance of vocabulary the writer hereby gives Paul’s statements on his book How to Study in College his argument is around the importance of a good vocabulary in speaking, reading, learning and thinking.
In speaking, people usually know what they mean by word expressed in written form or in isolation but they cannot express it clearly. According to Paul, this happens caused by inadequate vocabulary. Plato in Paul book stated that to transmit ideas, a speaking must paint picture in minds of listener by precise words.
In reading, there is a tendency to misinterpret meanings because of inadequate vocabulary. Moreover, in thinking if the vocabulary is limited, so that the thinking will be limited as well.
According to David Wilkins as quoted by Scott Thornbury said: “Without grammar very little can be conveyed, without vocabulary nothing can be conveyed”. David Wilkins assumed that “if you spend most of your time studying grammar, your English will not improve very much. You will see most improvement if you learn more words and expressions. You can say very little with grammar, but you can say almost anything with word”.
Vocabulary is important component that the students must master for learning. If they master vocabulary, they can understand what they read and they can do assignments in English book easily. However, vocabulary cannot be completely separated from other language skill and language constituent.
So it can be conclude that the students have to master vocabulary, because with vocabulary we can speak a fluent sentence in English and it is very important to support the students to master the four language skills, reading, listening, speaking and writing.
In addition, the mastery of vocabulary is an important indicator both in receptive and productive way of communication. Accurate and appropriate comprehension or interpretation of words in communication will have positive effect on comprehension or interpretation of the message or information transmitted.
Jeremy Harmer states if language structures make up the skeleton of language, then it is vocabulary that provides the vital organs and the flesh. An ability to manipulate grammatical structure does have any potential for expressing meaning unless words are used.
And then, about the definition of vocabulary such as mentioned above that vocabulary is very important in producing a language So, it can be said that the rich achievement of vocabulary means a result of the students' ability in mastering English, which can be measured by evaluation or test shown in letter, symbol or score.
 David Nunan, Language Teaching Methodology; a Textbook for Teacher, (New York: Prentice Hall, 1991), p. 117
 Walter Paul, How to Study in College, Third Edition, (New York: Houghton Milan Company, 1989), P. 270
 Scott Thunbury, How to Teach Vocabulary. (England: bluestone press, 2002), Op. Cit., p. 13
 Jeremy Harmer, The Practice of English Language Teaching, New Edition, (New York: Longman Publishing, 1992), p. 153