Can robots teach writing? Quill.org is betting so. The mostly free writing instruction platform, which has backing from the Bill & Melinda Gates Foundation and Google.org, uses machine learning to analyze and correct students’ grammar and sentence structure in real time. Already at use in 5,000 schools by around 700,000 students, Quill.org particularly targets lower-income K–12 students who tend to lack access to adequate language instruction, including the development of strong writing skills. Students take a diagnostic assessment to start with, then Quill.org’s algorithm devises a learning program tailored to their needs. Many teachers in resource-strained schools struggle to deliver high-quality writing instruction in particular, so Quill.org is hoping to close that gap one well-composed sentence at a time.