High school teachers typically do the following:

• Plan lessons in the subjects they teach, such as biology or history
• Assess students to evaluate their abilities, strengths, and weaknesses
• Teach students in full class settings or in small groups
• Adapt lessons to any changes in class size
• Grade students' assignments and exams to monitor progress
• Communicate with parents about students' progress
• Work with individual students to challenge them, to improve their abilities, and to work on their weaknesses
• Prepare students for standardized tests required by the state
• Develop and enforce classroom rules and administrative policies
• Supervise students outside of the classroom - for example, at lunchtime or during detention

High school teachers generally teach students from the 9th through 12th grades. They usually specialize in one subject area, such as math, science, or history. They may teach several different classes within that subject area. For example, a high school math teacher may teach courses in algebra, calculus, and/or geometry.

High school teachers may teach students from different grades throughout the day. For example, in one class they may have students from the 9th grade and then in the next class they may have 12th-grade students. In many schools, students are divided into classes on the basis of their abilities, so teachers need to change their courses to match the students' abilities.

High school teachers see several different classes of students throughout the day. They may teach the same material - for example, world history - to more than one class if the school has many students taking that subject.

Some high school teachers instruct special classes, such as art, music, and physical education.

When they do not have classes, teachers plan lessons, grade assignments, and meet with other teachers and staff.

In some schools, teachers of English as a second language (ESL) and teachers of English for speakers of other languages (ESOL) work exclusively with students who are learning the English language. These students are often referred to as English language learners (ELLs). These teachers work with students individually or in groups to help them improve their English language skills and help them with assignments for other classes.

Students with learning disabilities and emotional or behavioral disorders often are taught in traditional classes. Therefore, high school teachers may work with special education teachers to adapt lessons to these students' needs and to monitor the students' progress.

Some teachers maintain websites to communicate with parents about students' assignments, upcoming events, and grades. For students, teachers may create websites or discussion boards to present information and to expand a lesson taught in class.

Some high school teachers coach sports and advise student clubs and other groups, activities that frequently take place before or after school.