Indiana University
Juan M. Soto: Reglas Preterite and Imperfect
Concise, but thorough English explanation of the preterite and imperfect tenses in Spanish grammar. Great review for advanced students or teachers who want a quick review. Links are also available to interactive exercises and sheets that...
University College London
University College London: Survey of English Usage: Verbs Tense & Aspect
This site has information on the tense and aspect of verbs. Includes a short exercise to test your knowledge.
English Club
English Club: Learn English: Grammatical Category Quiz
A ten-question quiz about grammatical categories including: number, case, gender, person, tense, aspect, mood, voice, and degree.
English Club
English Club: Learn English: Grammatical Category
An explanation of grammatical categories including: number, case, gender, person, tense, aspect, mood, voice, and degree. A link to a grammatical categories quiz is also available.