First Conditional

http://www.englisch-hilfen.de/en/exercises/if1.htm

Simple past X Past progressive

1. http://www.pacificnet.net/~sperling/quiz/past1.html

Present perfect

1. Questions
http://www.isabelperez.com/perfect-ex.htm

2. Simple Past X Present Perfecthttp://www.pacificnet.net/~sperling/quiz/past2.html

3. Simple Past or Present Perfect?http://www.pacificnet.net/~sperling/quiz/iverb1.html

Comparative or superlative?

Superlative
http://www.isabelperez.com/super.htm


2.Comparative or superlative?
http://www.isabelperez.com/super-sign.htm


3.Comparative
http://www.isabelperez.com/comp.htm