Abstrak
This research was conducted to (1) identify and describe the types of errors in narrative text made by the fourth semester students majoring in English education at the Borneo Tarakan University (UBT); (2) find out the frequency of types of the errors; (3) identify and describe the sources of the errors. The subjects of this study were 29 third semester students. Data were collected by asking the students to write narrative text with the given topics. To get information about possible causes of the errors, 6 students were interviewed. The results showed that there were totally 140 errors found in students’ writings which were analyzed using Surface Strategy Taxonomy. They consisted of 55 omission errors, 62 addition errors, 17 formation errors, and 6 placement errors. Meanwhile, based on the comparative analysis taxonomy, 77 errors were caused by developmental factor, 25 errors by interlingual factor, 29 errors by ambiguous factor, and 9 errors by other factors. In conclusion, the students’ grammatical errors were due to their lack of grammar understanding and the influence of indonesian structure in the process of learning English.