As a result of the widespread adoption of big data technologies in the classroom, traditional pedagogical practices have seen profound shifts, and students are now able to take an active role in their own education rather than passively receiving information from their instructors. The proliferation of learning materials is another consequence of big data’s meteoric rise to prominence. An online system for teaching English grammar is primarily researched and developed in this work, with a focus on big data. It begins with an examination of how big data has altered the landscape of English grammar instruction, moves on to specify the needs for online grammar instruction, develops research methodologies to meet those needs, plans the architecture and functionality of an online grammar instruction system that leverages big data, and concludes with a survey of current English teachers to gauge their level of comfort with online grammar instruction. The findings of the investigation reveal that the twenty English instructors surveyed are not very acquainted with or accepting of online grammar instruction.