The objectives of the research are to find out (1) the types of errors made by students; (2) the percentage of errors; and (3) the causes of errors made by students in writing analytical exposition text. This is a descriptive qualitative research, carried out in November 2016. The population of this research was the eleventh grade students in SMAN Karangpandan. Class XI IPA 1 consisting of 39 students was taken as the sample of the research by using cluster random sampling technique. The instruments used to collect the data were test and interview. The data were analyzed by using error analysis procedures which consist of collecting the data of errors, identifying the errors, describing and classifying the errors, explaining the errors, and evaluating the errors. There were 1279 errors made by students which were classified into error in omission (469 or 36.67%), addition (213 or 16.65%), misformation (531 or 41.52%), and misordering (66 or 5.16%). Those errors were caused by two factors: (1) interlingual transfer which is caused by the influence of the first language (241 errors or 18.84%); and (2) intralingual transfer which refers to the negative transfer of items within the target language (1038 errors or 81.16%). From the research, it can be seen that most of students did not understand that there are some rules in constructing grammatically correct sentences in English. Therefore, teachers need to encourage the students to learn about English grammar so that students will be able to produce a good text.
Keywords : grammatical errors, error analysis, analytical exposition text