English language has some sentence types used in writing. The complex sentence
is one of the sentence types that occur in writing. However, in the practice, it is
found that some students still make errors and have difficulties in writing it. This
study attempted to find the kinds of error on constructing complex sentences in
students’ writing. The purpose of this study is to identify the errors in the
students’ writing of English Education Study Program at STKIP PGRI Sidoarjo
on the use of complex sentences. The methodology used in this study is
descriptive qualitative method. The source of data of this study was the errors of
complex sentences taken from the seventh semester students’ written task of
English Education Study Program at STKIP PGRI Sidoarjo. This study found that
there were 74 errors in students’ writing on constructing complex sentences. The
errors of complex sentences were classified into errors of omission, errors of
addition, errors of misformation, and errors of misordering. There were 70% of
errors of misformation, 23% of errors of omission, 4% of errors of addition, and
3% of errors of misordering. Many students still made errors in using the correct
form of verb in complex sentences which considered as error of misformation.
The students are supposed to try many times on writing complex sentences using
correct form of verb.