Sentence+Combining

http://sentence-combining.wikispaces.com/

Grammar Self Tests http://www.wadsworth.com/devenglish_d/special_features/grammarquizzes.html

More Grammar Exercises http://www.englisch-hilfen.de/en/exercises_list/alle_grammar.htm

Parts of Speech Practice http://web2.uvcs.uvic.ca/elc/studyzone/330/grammar/parts1.htm

More Grammar Quizzes http://www.softschools.com/quizzes/grammar/