This descriptive study aims at: (1) finding out and describe the phonological, lexical, and syntactic forms of English language learners' inter language, and (2) finding out whether there are any differences in the inter language of the learners of different grades. The subjects of this research were 24 learners of the first, second, and third grade of an Islamic boarding school in Tasikmalaya. The data were collected from students' conversations, interviews, and reading aloud. The data were recorded and transcribed. Then, the data were filtered by using Corder's procedure. The results of the research reveal the existence of the following aspects in the learners' inter language: (1) phonological transfers, (2) lexical transfers, (3) syntactic transfers, (4) phonological overgeneralizations, (5) lexical overgeneralizations, and (6) syntactic overgeneralizations. This research also found out some differences in the inter language of the students of different grades.
Keywords: inter language, pesantren, phonological, lexical, syntactic, language transfers, overgeneralizations