Options for finding help writing correct sentences include finding a tutor, reviewing grammar rules online and using free online quizzes to check your understanding. Purdue OWL's website offers guides and exercises to improve sentence construction and editing.
Purdue OWL provides a free resource for both grammar and citation assistance. The grammar section provides links and explanations regarding all parts of speech to aid in sentence creation and correction. The grammar exercises allow users to practice and quiz themselves on common grammar mistakes and proper usages. The University of Chicago offers a collection of links that aid in sentence creation in multiple disciplines. The options range from simple grammar rules to more complicated style guides and rules for specific disciplines.
Edufind.com's grammar guide also offers full explanations of all English grammar rules. The site breaks the rules down into accessible links to short articles that provide detailed examples. Grammarbook.com offers free grammar rules with interactive quizzes that evaluate a student's understanding of the rules.
In addition to online resources, many colleges and universities offer tutoring in grammar and writing, and paid tutoring is often available in many areas. Local libraries offer books on the topic, and librarians are frequently well-versed in grammar rules and conventions.