Beginning (A1+)

• Allset Learning Grammar Wiki
• Modern Mandarin Chinese Grammar: A Practical Guide
• Basic Patterns of Chinese Grammar
• Schuam's Outlines of Chinese Grammar

Intermediate (B1+)

• Yufa! A Practical Guide to Mandarin Chinese Grammar, 2nd ed.
• An A to Z Grammar for Chinese Language Learners (traditional only) ISBN 9789570851069
• Common Chinese Patterns 330
• A Guide to Proper Usage of Spoken Chinese

Advanced (C1+)

• Chinese A Comprehensive Grammar
• 實用現代漢語語法 (Mandarin only)
• Error Analysis of 900 Sample Sentences
• A Learn's Handbook of Modern Chinese Written Expressions
• Using Chinese Synonyms by Grace Qiao Zhang
• Chinese Synonyms Usage Dictionary ／《漢語近義詞用法詞典》 by 鄧守信