eMints at emints.org is a professional development site for educators from elementary school through college. It offers a number of proofreading exercises. The Exercise in Capitalization is an online activity where respondents read through a number of sentences and denote 80 words in the text with a "C" for correct or an "I" for incorrect. This exercise covers such areas as state names, surnames and titles. Upon completion, the exercise is submitted and scored electronically.
Purdue University's Online Writing Lab (OWL) has proofreading exercises covering such topics as grammar, punctuation, spelling, sentence structure and writing numbers. OWL exercises can be printed out and complete answer keys are available online. Individual exercises focus on specific areas including prepositions, proper use of adjectives and adverbs and subject-verb agreement.
Each OWL exercise is prefaced by a tips page that provides an overview of the topic covered in that exercise.
JournalismCareers.com, an online resource for editors and writers, provides a proofreading exercise on its website. The proofreading exercise consists of a 900-word article, which can be printed out and then proofread using standard proofing marks. Alternatively the article can be copied and pasted into a word processing program for electronic proofing.