Abstract. This study investigated the effectiveness of literacy strategies on students' English language proficiency in vocabulary, reading comprehension, and written expression. It also sought to determine whether the students' perceived effectiveness of these strategies influenced their English language proficiency. The researchers employed a quasi-experimental and descriptive-correlational design. The participants were the 10th-grade students of Camanjac National High School. The study used parallel 45- item English pre-and posttests and a survey questionnaire to fit the purpose of the study. These tests and survey questionnaires were subjected to content validation by experts. The respondents underwent the entire procedure: the pretest, the utilization of literacy strategies, and the posttest. The researchers used weighted mean, percentage, t-test, and Spearman rank correlation coefficient in treating the data. In the pretest, the students scored below expectations in vocabulary, reading comprehension, and written expression, with mean scores of 73.42 percent, 69.27 percent, and 70.58 percent, respectively. The posttest revealed that the level of English proficiency after using literacy strategies improved to 82.19 percent in vocabulary, 81.72 percent in reading comprehension, and 82.08 percent in written expression. Furthermore, the t-test results indicate that the students' performance significantly improved. In addition, the data disclosed a significant relationship between reading strategies and the students' reading comprehension levels. However, there is no significant relationship between vocabulary strategies and the students' vocabulary level, nor between writing strategies and the students' written expression level.

Keywords: Literacy strategies; English language proficiency; Reading comprehension; Vocabulary; Written expression.