Adjective Clauses

1. When/Where:  Explanation and Practice (grammar-quizzes.com)
2. Whose:                   Explanation and Practice (grammar-quizzes.com)
3. Who / Whom / Whose (englishpage.com)
4. Who/Whom/Which/That Explanation and Practice (web2.uvcs.uvic.ca)/
5. more explanations
6. Who/Whom more explanation and exercises