Colby College provides a large collection of exercises on adjectives, adverbs, numbers, prepositions, clauses, study modules, and more.

Great practice with idioms that use the verb "estar". Also provides practice conjugating the verb in present, preterite, imperfect, future, and conditional tenses--a different practice test for each tense. Answers may be verified after...

This site contains multiple vocabulary tests of 100 words each that drill word sets from animals to words of the soul. It also contains grammar quizzes and a personalized test generator.