This study was conducted based on the opinion that language is something that can be mastered either by acquiring or learning process. In our national education system, English becomes a subject that must be taken by the students in formal educational institution like elementary, junior and senior high school until university and also becomes an additional subject for the students in informal educational institution like pesantrens.
There are two types of pesantren. The first is modern pesantren and the second is traditional pesantren. Modern pesantrens are pesantrens that use modern method in their teaching and leaarning. Traditional pesantrens are pesantrens that use traditional method in their teaching and learning. These two types of pesantrens have a unique pattern in their teaching and learning that may have influences to their students in English ability.
The researcher were interested to analyze the English ability of students were graduated from modern and traditional pesantren by comparing their achievement in English I class. The researcher chose the students of IAIN Walisongo Semarang as population in this study, and the sample was the students from Arabic department. The Arabic department students was chosen because most of them were graduated from pesantrens.
In this study, the researcher used a comparative study. Comparative study is a descriptive study that compares between two or more situations, phenomena, activities and others which are similar, and it is used to find the similarities or the differences.
In collecting data, the researcher used test, interview and documentation method. In test method, the researcher used an achievement test to measure the students’ ability in English. Interview was done to get data that needed in this research. The data was goten from students were graduated from modern and traditional pesantrens. The documentation used in this research was students name list, profile of pesantrens, educational system in pesantrens.
The SPSS result showed that score of ttest = 4.515 and ttable = 2.10. The criteria is ttest > ttable, so Ha accepted and it means that the English ability of students’ graduate from modern and traditional pesantrens is not identical.
Based on the result of this study, the ability of modern pesantrens graduate is better than traditional pesantrens graduate in English achievement. It caused that in modern pesantrens, they used a bilingual system in their daily activities whether in traditional pesantrens they just used monolingual in their daily activities.