Connectives (e.g., although, meanwhile) carry abstract meanings and often signal key relationships between text ideas. This study explored whether understanding of connectives represents a unique domain of vocabulary knowledge that provides special leverage for reading comprehension, and whether the contribution of knowledge of connectives to reading comprehension differs for students from distinct language backgrounds. Understanding of connectives, word reading efficiency and breadth of vocabulary knowledge of 75 English language learners (ELLs) and 75 English-only (EO) fifth graders were assessed. Hierarchical multiple regression techniques revealed that understanding of connectives explained a sizeable and significant portion of unique variance in comprehension beyond that explained by breadth of vocabulary knowledge when controlling for word reading efficiency. The magnitude of this relationship was larger for EO students than for ELLs. Findings indicate that connectives play an important role in comprehension, but that the strength of their influence varies by readers' linguistic background. (Contains 3 notes, 6 tables, and 1 figure.)