This research investigated vocabulary, grammar and function of English which could work well as a means of conducting: 1) the application of instruction (students’ physical behaviors, giving orders or tasks), 2) the science instruction (imparting theories, the concepts, facts and information) and 3) vocabulary instruction (helping the students understand vocabulary). The research found three kinds of word used by the teachers namely: 1) High Frequency General Words, 2) Non Specialized Academic Words and 3) the Specialized Content Area Words. The category 1) were used for social function to build interpersonal communications, direct the students’ physical behaviors and give the orders or the tasks. The category (2) and (3) were used in the area of academic function specifically to conduct the science instruction (explanations, descriptions, comparisons, assessments, clarifications, paraphrasing, directing instructions, and behaviors). Four sentence patterns (declarative, interrogative, imperative and exclamatory) were used for the application of instruction such as greetings, leave-takings, appreciating the students’ works, directing the students’ behaviors and the students to do the tasks. In the context of science instruction, the declaratives were used for explanations, descriptions, comparisons, clarifications and paraphrasing. Assessing the students’ knowledge and doing the clarifications used interrogative sentences. The imperative sentences were used for directing the instructions and the students’ behaviors. The exclamatory sentences were used to express the teachers’ excitements, admirations or angers. The Noun-Phrase patterns with past-tense and non-past tense and its transformational forms were employed.