PREPOSITIONS

Some theory about time and place prepositions:

http://grammar.ccc.commnet.edu/grammar/prepositions.htm

Don´t miss the "select from the following" section. You´ll be surprised!

The meaning of prepositions in Spanish

http://www.ompersonal.com.ar/omgrammar/listadepreposiciones.htm

Some exercises

http://www.englishpage.com/prepositions/prepositions.html

http://www.englishexercises.org/buscador/buscar.asp?nivel=any&age=0&tipo=any&contents=prepositions#a

http://www.englishforjapanese.com/exercises/prepositions/01%20preps.html

http://www.autoenglish.org/prepositions.htm

http://www.agendaweb.org/grammar/prepositions-intermediate-exercises.html