Tom, who felt too sick to work fast,

66

c. The Use of Punctuation Commas

In Table 9, the researcher presents the number and the percentage of each error category. In this case, students’ errors in the third category, the use of punctuation commas, fill the highest rate. This category has 349 errors with percentage 45.34. In the research, the researcher analyzes the errors’ classifications based on surface structure taxonomy. In order to classify the errors, the researcher divides the errors into three types of errors in the use of punctuation commas. Table 10 presents classifications of students’ errors in the use of punctuation commas. Table 10. Classifications of Students’ Errors in the Use of Punctuation Commas Type of Errors Classifications Example 1. Omitting commas in non-defining relative clauses Omission 302 92.64

16. Tom, who felt too sick to work fast,

had a hangover. 2. Adding commas in defining relative clauses Addition 24 7.36 15. The report, which should have taken an hour and a half, took three hours. Total 326 100 Notes: symbol means number and symbol means percentage Table 10 displays classifications of students’ errors in the use of punctuation commas. The table needs five columns. The first column is types of students’ errors in the use of punctuation commas. The second column is the classifications of each type of the students’ errors in the use of punctuation commas. The third column is the number of errors in the use of punctuation commas in each type. The fourth column is the percentage of errors in the use of punctuation commas in each type. It is obtained by dividing the number of errors in the use of punctuation commas in each type by the total number of 67 errors in the use of punctuation commas, then multiplying the result by 100. The last column is the examples of students’ errors in the use of punctuation commas. Table 10 describes that there were 326 errors in the use of punctuation commas in the test. The researcher grouped those errors into two types. Those types were omitting commas in non-defining relative clauses and adding commas in defining relative clauses. The first type, omitting commas in non- defining relative clauses, had 302 quotas. It was the highest number of errors in the use of punctuation commas. It is about 92.64. The second type was adding commas in defining relative clauses. It filled the second position with number of 24 errors and percentage of 7.36. The number of this type was much lower than the first type. The examples prove that the students made errors in each type of errors in the use of punctuation commas. The first example showed the students made omission errors. The students often omitted commas as the punctuation needed in constructing complex sentences with non-defining relative clauses. In item number 16, the students missed commas in constructing complex sentences with non-defining relative clauses. Those sentences should have commas to indicate that relative clauses within the sentences are non-defining relative clauses. The construction should be “Tom, who felt too sick to work fast, had a hangover.” Based on the research, the students often missed commas in the sentences using non-defining relative clauses. The students need to learn relative clause more in order to avoid misunderstanding in using commas in relative clauses. 68 The last example presents the students’ addition errors. The students added commas in defining relative clauses. Actually, complex sentences with defining relative clauses do not need commas. Relative clauses need commas to show that they function as non-defining relative clauses, giving additional information of the noun modified. Item number 15 described that the students added commas in a complex sentence with a defining relative clauses. As it is explained before, defining relative clauses do not need commas to separate it from the main clause. A defining relative clause aims to give crucial information of the antecedent. On the other hand, commas separate a non-defining relative clause, not a defining relative clause, from the main clause in order to give additional information. Therefore, a complex sentence containing a defining relative clause does not need commas to separate the relative clause. The sentence in item number 15 should be “The report whichthat should have taken an hour and a half took three hours.” In this research, it can be concluded the students still had problems in constructing complex sentences with defining and non-defining relative clauses, especially in the use of commas in non-defining relative clauses and the absence of commas in defining relative clause. Those problems showed that the students still did not understand in the use of commas in non-defining relative clauses. They need to learn defining and non-defining relative clauses more so that they can produce complex sentences using relative clauses correctly. 69 After discussing the students’ errors of defining and non-defining relative clauses, the researcher discovered the findings of the second research question. Those findings were:

1. English Language Education Study Program students made 719 errors or 29.96