Correlating Vocabulary and Sentence Structure Mastery to Students’ Writing Skill in Descriptive Text

The aims of the research are to find the correlation between vocabulary and sentence structure mastery towards students’ writing skill. This research also calculates how strong the correlation by analyzed and computed using Pearson Product Moment. The method used in this research is quantitative research method by implementing a correlation study research design that has three variables. The first variable is vocabulary mastery, the second is sentence structure mastery, and the third is students’ writing skill in descriptive text as dependent variable. The researcher gives three tests to 40 students. That test is given to measure student’s abilities according to the three previous variables. The result of this research is the use of correlation between vocabulary mastery and sentence structure mastery toward students’ writing skill. The finding of the research proves a moderate level of correlation. This study suggest that the students have to learn vocabulary mastery and sentence structure mastery, and the English teacher should prioritize it so students’ writing skill will improve.


Introduction
English teacher is supposed to be able to teach her students both language components and language skills. One of the language skills is supposed to teach is writing skill. In school, writing is taught for the students in order to make the students have ability in writing. However, in the reality, so many students have less ability in writing although they had been taught by the teacher.
The main factors that makes writing is not easy for the tenth grade students of Senior High School Kramatwatu that they cannot recognize or improve a sentence or paragraph However, they must write, make, and put it into a good sentence. Therefore, the students 48| Vol. 4 No. 1, 2021 must have good ability in vocabulary to support other skills. Without mastering vocabulary along with pronunciation, the students cannot improve their language well (Septiyani, Hikmah, & Baihaqi (2019). It has to be realized that the students' writing skill is conditioned by their knowledge of vocabulary. The students have lack of vocabulary will unable to use the structure in making good sentence and it will influence of their writing skill.
Moreover, they cannot put the right words down becoming a good sentence.
Another problem is although they have an idea but they are still confused how to develop it as the correct one, so they cannot make a good sentence or paragraph because of their understanding about the sentence structure is very low.
In grammar, a sentence is a basic grammatical unit. A sentence consists of a subject and a predicate. Sentence has a structure such as simple, complex, and compound sentence. Those also become an important role of the writing skill. That is why the important of vocabulary mastery and sentence structure mastery can be related to writing skill, especially in descriptive text because descriptive text is one of types of writing using simple present tense. The researcher observes that the students sometimes make a mistake in composing a simple sentence structure.

Method
The research emphasizes on the correlation of vocabulary mastery and sentence structure mastery towards students' writing skill in descriptive text at tenth grade of SMAN 1 Kramatwatu. The researcher used quantitative research method by implementing a correlation study research design who has three variables. The first variable is vocabulary mastery, the second is sentence structure mastery, and the last is students' writing skill in descriptive text as dependent variable. The first and the second are independent variables. Therefore, the researcher sees clearly throughout the research design in the following figure.  Therefore, the result of r is reffered to such categories above and it can be determined the correlaton level of two or more items.

Result
In this context, the researcher will look for the multiple correlation between two independent variables and one dependent variable. The formula which will be used as stated in the previous chapter as follows.
Rx 1 x 2 y = √ To find this correlation, some steps have to be taken. It will be explained one by one in the next calculation below.
Firstly, it has to be found the correlation between vocabulary mastery and writing skill, which was computed previously and the result is 0,44440389, so it does not need to count again. Secondly, the researcher found the correlation between sentence structure mastery and writing skill. The result of this correlation, in fact, has been determined, and it is 0,383417755. The third steps to carry out such correlation is finding the correlation between vocabulary mastery and sentence structure mastery. To get the result, it can be defined as follows. After having the result of the correlation between vocabulary mastery and sentence structure mastery, which is 0,945716596, the next step is to find multiple correlation based on the formula mentioned above.
Rx 1 x 2 y = √ It means that Ho is rejected and H1 is accepted. Therefore it can be summarized that there is medium correlation between vocabulary mastery and sentence structure mastery, and writing skill.
Since there is a correlation between vocabulary and sentence structure mastery towards students' writing skill, this research result categorized as medium correlation and supports the previous theories that writing not only involves knowledge to produce, understand, and apply sentences but also inculdes vocabulary knowledge which refers to the knowledge of words as well as meaning of words. It is suggested students to learn vocabulary and sentence structure mastery to improve their writing skill.

Conclusion
The result proves that there are significant correlation between vocabulary mastery and sentence structure mastery towards students' writing skill in descriptive text at tenth grade of SMAN 1 Kramatwatu.
That is proved by the result of (r) is 0,458650333. Having calculated that result, this value then is compared with (r) table, which has coefficient significance 5% is that 0.34. The comparison outcome of two items indicates that (r) calculation is higher than (r) table. The consequence of this one is that there is medium correlation between vocabulary mastery , sentence structure mastery, and writing skill.
There are significant correlation between vocabulary mastery towards students' writing skill in descriptive text at tenth grade of SMAN 1 Kramatwatu. That is proved by the result of (r) is 0,444403893.
Having calculated that result, this value then is compared with (r) table, which has coefficient significance 5% is that 0.34. The comparison outcome of two items indicates that (r) calculation is higher than (r) table.
The consequence of this one is that there is medium correlation between vocabulary mastery and writing skill.
There are significant correlation between sentence structure mastery towards students' writing skill in descriptive text at tenth grade of SMAN 1 Kramatwatu. That is proved by the result of (r) is 0,383417755.
Having calculated that result, this value then 55| Vol. 4 No. 1, 2021 is compared with (r) table, which has coefficient significance 5% is that 0.34. The comparison outcome of two items indicates that (r) calculation is higher than (r) table.
The consequence of this one is that there is low correlation between sentence structure mastery and writing skill.