Google Docs can be used for collaborative language learning in three main ways: 1. Collaborative writing projects allow students in different locations to jointly create documents while the teacher can see each student's contributions. 2. It provides a shared online workspace where users can simultaneously edit documents and students and teachers can share workspaces, such as using it as an online whiteboard. 3. Students can use it as a personal learning environment by taking notes online, embedding learning materials, and creating a portfolio of student work.