Schaum's Outline of German Grammar by Elke Gschossmann-Hendershot
Designed to make the study of German grammar a lot easier, this edition of this popular book covers all the problem areas of the language: nouns and pronouns; articles; prepositions; adjectives and adverbs; verbs; numbers; and much more. The Third Edition features updated vocabulary, a new chapter on the sounds of German, clear explanations of grammar, and a subject index to make material more accessible.