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Univ. Of Southampton: Wessex Parallel Web Texts: Intro to Traditional Grammar
If the terms of grammar are foreign to you, this is a good basic place to start. Each term is defined with examples and brief commentary.
Capital Community College Foundation
Guide to Grammar and Writing: Parallel Structures Quiz
Capital Community College provides this 9 question quiz to test your knowledge of solid sentence writing. Each answer will be explained when you hit the "Submit application," button at the end of the quiz.
English Plus+
English Plus: Comparison Problems
A list of five common problems writers face when using comparisons. Each problem is explained, the wrong usage is demonstrated, and the correct usage is demonstrated.