Investigating Grammatical Errors in EFL University Students' Argumentative Essays

The objective of this study is to analyse grammatical errors in argumentative texts written by university students, with a specific focus on identifying the most common errors and determining their underlying causes. This study applied an explanatory mixed-method design. The researchers employ the Surface Strategy Taxonomy to identify errors. The results indicate that students make four types of errors: omission (63%), addition (27,5%), misformation (5,7%), and misordering (3,8%). The study found that omission errors were the most common, whereas misordering errors were the least common. The interviews revealed that sentence structure problems in students' writing were influenced by both interference from their mother tongue and the tendency to overgeneralize English rules and norms.