文法教學與溝通式教學在第二外語學習過程中一直是爭議不斷的議題。儘管在外語教學過程中，一直強調溝通式教學法，然而各種研究亦顯示文法教學有助於成年學生學習外語。因此本研究針對較難之文法時態「過去完成式」，比較兩種教學法之成效。研究對象為台灣北部某大學65位大一非英語系學生，隨機分為兩組，一組採用文法教學法，另一組採用溝通式教學法。課後立即進行測驗，其內容包括文法測驗及段落寫作。結果顯示，文法教學組不論在文法測驗或是段落寫作上，都明顯優於溝通式教學組之成績。

The issue of the role of grammar instruction in L2 learning/teaching as opposed to a communicative approach is controversial. While communicative approaches have been greatly promoted in language teaching, research has suggested that grammar instruction can make a difference for L2 acquisition and speed the learning process for adult learners. The present study examines the effect of teaching the past perfect tense to adult EFL learners in a university in northern Taiwan, using two different instructional approaches. Sixty-five participants were randomly assigned to two groups, with one given form-focused instruction and the other, communication-focused instruction. A posttest containing a one-paragraph writing task and a grammar recognition test was given to the learners in each group immediately after instruction. Results show that the participants in the grammar group outperformed those in the communicative group in both the grammar recognition test and the writing task.