This thesis compares significant linguistic features of English and Bahasa Indonesia (BI) and examines possible effects of language transfer for Indonesians who speak English as a second language (L2). The thesis first presents a description of BI: 1) phonology (vowels, consonants, stress and intonation), 2) word order (SVO and other alternatives, relativization, nominalization, topicalization, questions), 3) the noun phrase (derivation of nouns, modifiers in noun phrases, demonstratives, plurals, personal pronouns), and 4) the verbal system (derivation of verbs, agreement, copulas, passive voice, negation, tense, adverbs, modals/auxiliaries). For the IRB-approved research study, the researcher interviewed ten Indonesians from diverse linguistic, cultural, and educational backgrounds about their experiences learning English and asked them to tell a story in order to elicit use of the past tense. The research sought to determine which errors Indonesian L2 speakers of English often make and which of these errors can be attributed to language transfer. Also, the study examined whether participants seem to be aware of their errors and what pedagogical implications may arise from these findings. Interviews were transcribed, then errors were coded and analyzed to see if the errors that Indonesians often make while speaking English correspond with the main differences between English and BI. The most common error was verb tense. After that, the next most common errors were articles; plurals; prepositions; other verbs; omission of "be" verbs; adjectives; omission of subjects; subject/verb agreement; and languages
ationalities. The thesis also discusses participants' perceptions of differences between BI and English and perceptions of difficulties when learning English, and how these perceptions correspond with their performance in English. While it seems that many of the errors that Indonesian L2 speakers of English are due to language transfer, others are not. Virtually no research has been carried out on language transfer from BI to English, so there is much future research that can be conducted on Indonesians learning English. Language transfer is just one of the relevant topics in the field.