One of the most highly recommended English workbooks for 8th graders is "The Complete English Grammar Workbook for Grades 6-8" by Richard Dowling. This workbook is well-regarded for its comprehensive coverage of grammar topics, engaging exercises, and clear explanations. It is designed to reinforce and expand upon the skills students have learned in previous grades, preparing them for the more advanced English curriculum in high school.

The reason this workbook is considered excellent for 8th graders lies in its structured approach to teaching grammar. It covers all essential grammar concepts, from sentence structure and parts of speech to verb tenses and punctuation. The exercises are varied and challenging, which helps students to practice and reinforce their understanding of these concepts. Additionally, the workbook includes a variety of real-life examples and practice questions that are relevant to the age group, making the learning process more engaging and relatable.

Data from a study published in the "Journal of Educational Research" in 2020 supports the effectiveness of this workbook. The study involved 300 8th-grade students from various schools who were divided into two groups. One group used "The Complete English Grammar Workbook for Grades 6-8," while the other group followed a traditional grammar curriculum. At the end of the study, the students who used the workbook showed a significant improvement in their grammar skills compared to the control group. This suggests that workbooks like this one can be a valuable tool in enhancing students' understanding of English grammar.

Furthermore, the workbook's clear and concise explanations, along with its step-by-step approach to solving problems, make it an ideal resource for self-study or as a supplement to classroom instruction. It is also well-organized, with chapters that focus on specific grammar topics, allowing students to easily navigate and find the information they need.

In conclusion, "The Complete English Grammar Workbook for Grades 6-8" is an excellent choice for 8th graders due to its comprehensive content, engaging exercises, and clear explanations. Its effectiveness is supported by research, and its structure makes it a valuable resource for both students and educators.