The increase in global migration and the prioritization of English as an international language have resulted in science learning environments that include students whose primary language differs from the language of instruction. This worldwide phenomenon is not limited to geographical regions but occurs where diverse populations representing languages, cultures, ethnicities, and nationalities exist. English Language Learners (ELLs) in these classrooms face the task of learning science while learning to comprehend and participate in the discourse of science. Science teachers must therefore be strategic in providing experiences that will facilitate the development of ELLs' literacy skills to do and engage science learning. We present how one middle school science teacher, engaging in practitioner inquiry, tapped into the potential of deliberate cognate instruction to support the learning of science vocabulary within the context of inquiry-based science teaching. The 7th grade teacher adapted a graphic organizer that served to focus on ELLs learning core ideas and through deliberate cognate instruction connected their Spanish language to English. Cognates, in conjunction with other teaching strategies, proved to be an effective way for the simultaneous learning of disciplinary content knowledge and vocabulary words. The knowledge generated from this practitioner inquiry had immediate impact and though not generalizable can offer insights beyond this immediate classroom. The Spanish-English cognate was a viable tool in bridging the language differences; however, we acknowledge that limitations will occur in classrooms where the languages may not have common roots to support cognate instructions.