This document discusses substitution drilling as a technique for practicing grammar and useful phrases in the English language classroom. It begins with examples of substitution drills where the teacher provides a sentence with a replaced word for students to repeat. The benefits of substitution drilling are that it builds accuracy, fluency and confidence as students practice new language. Some techniques for drilling longer phrases include backchaining individual words or phrases and practicing intonation and sentence stress. The document provides examples of how to incorporate substitution drilling and useful language boxes into classroom activities like tic-tac-toe games. It encourages discussing different drilling methods and considers student feedback.