To effectively substitute teach English in junior high school, it's crucial to prepare thoroughly. Review the curriculum and identify key topics that will be covered during your session. Prepare relevant teaching materials such as worksheets, games, and activities that engage students and reinforce learning objectives.

On the day of the class, arrive early to familiarize yourself with the classroom setup and any technology you may need to use. Greet the students warmly and establish a positive rapport. Begin by briefly introducing yourself and setting clear expectations for behavior and participation.

Use visual aids like PowerPoint slides or handouts to enhance understanding. Provide frequent feedback on student performance and offer individual assistance when necessary. End the class with a recap of the main points covered and assign homework or reading to reinforce what was learned.

By preparing well, maintaining a positive attitude, and adapting your teaching style to suit the students' needs, you can ensure an effective and enjoyable substitute teaching experience.