We examined how a group of Chinese undergraduate students understood paraphrasing and source use conventions for research paper writing in English. Prior scholarship has generated valuable insights about novice second language (L2) writers’ unconventional source use practices, but little is known about how these writers interpret and understand source use expectations for English academic writing. We followed a group of nine Chinese undergraduate students for an academic term as they learned to paraphrase and write with sources for their research paper assignments. Drafts of students’ papers were collected and rounds of text-based interviews were conducted where students were asked to explain their source use decisions. Findings showed that the students actively and constantly referenced their source use knowledge of Chinese essay writing to help make sense of source use expectations for English academic writing, although their understanding of English academic source use as well as their rendition of culture may likely be viewed by expert academic writers as ‘insufficient’ or ‘inadequate’. We conclude by highlighting the importance of foregrounding learner voice and acknowledging the legitimacy of the interpretations of novice L2 writers as intercultural informants in the teaching of English academic source use.