English 9 and 10 ("Communicating Effectively") consists of parallel texts called Book One and Book Two. Either book may be studied first, which makes it possible for Grades 9 and 10 to be combined in one class if desired (each half of the students exchanging books for the second year). By default, in most homeschool situations students use Book One the first year and then Book Two the next.

Both books review grammar concepts from Grade 8 and previous years, but each one deals with different kinds of composition. Book One has 114 lessons and Book Two has 118 lessons. Both books have 15 tests (sold separately).

New grammar concepts include retained objective complements, nominative absolutes, subjects of infinitives, moods of verbs, and idioms.

Composition skills in Book One include lessons on listening and speaking, Bible study, outlining, argumentative essays, poetry, and letter writing.

Composition lessons in Book Two teach study skills, expository essays, stories, descriptions, reference sources, and parliamentary procedure.

Interspersed throughout both books are lessons to improve writing, speaking, and editing skills. Writing and speaking lessons focus on style rather than content.

Instead of a supplementary worksheets booklet, as in the lower grades, the tests booklet (sold separately) includes copies of the editing sheets found in the textbook, made available for repeat practice.