Capital Community College Foundation
Guide to Grammar and Writing: Abbreviations
A very competent look at how to use abbreviations in their proper context. This site also examines the proper use of abbreviations with titles, numbers and phrases.
University of Washington
Mary Nell's Grammar Summaries
The University of Washington provides an excellent collection of grammar-related summaries. The collection includes material on verb tenses, agreement, noncount nouns, and many other topics.
SMART Technologies
Smart: 4 Types of Sentences
Learn about the 4 types of sentences; interrogative, exclamatory, imperative, declarative