Machine translation tools are technically straightforward to use, but language learners may not instinctively know how to apply them effectively or responsibly to support their learning. Machine translation literacy is a new type of digital literacy that emphasizes critical thinking rather than focusing solely on techno-procedural skills. For language learners, machine translation literacy involves understanding how data is used by and influences data-driven translation tools (e.g. Google Translate, ChatGPT). It also means developing good judgement and being transparent and responsible with regard to tool use, as well as learning how to interact with tools in order to improve the translation quality. Instructors can support students by developing clear policies for machine translation use in their courses and offering structured guidance to help language learners experiment with and compare different tools and use cases.