The present study aims to shed light on analyzing the types and the frequency of the written sentence errors committed by 58 tenth grade Turkish Cypriot English as a foreign language (EFL) students in two classrooms, that is, Class A and B at a public vocational high school in North Cyprus. A quasi-experimental design was employed in the study where Class A was the experimental group which was exposed to an audio-visual aid titled "the Little Red Riding Hood" and Class B who acted as the control group. Data were collected from the written sentences produced by the students. All the errors committed by the students were identified and categorized into syntactic, morphological, orthographic, and lexical categories. The results of the study showed that both classes of students committed 11 types of common errors: (a) wrong use of articles, (b) wrong use of prepositions, (c) word order, (d) verb tense, (e) omission of plural -s, (f) misuse of the possessive -s, (g) incorrect use of comparative adjectives, (h) incorrect spelling, (i) punctuation, (j) capitalization, and (k) wrong words. However, the experimental group committed less errors (N = 232, 57.14%) as compared to the control group (N = 320, 78.82%). The findings have implications for EFL teachers to incorporate audio-visual aids into their teaching methodologies when teaching the writing skill.