Comparatives and Superlatives

http://www.clafoti.com/imagenes10/compa_1.htm

Modal Verbs

http://www.xtec.es/~ogodoy/sac/rephrasing/rephrexercises.htm

Listening Practice (different levels)

http://www.ompersonal.com.ar/omlisten/contenidotematico.htm

Verb Tenses Practice

http://www.e-grammar.org/present-simple-continuous/

KET test online

http://olpt.s3.amazonaws.com/online-practice-ket/index.html

Gerunds and Infinitives

http://www.englishpage.com/gerunds/index.htm