ESO4: Past Simple & Present Perfect: For, since and ago

For, since and ago: extra exercises.

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-49804.php
http://www.esl-lounge.com/student/grammar/2g3-for-since-gap-fill.php
http://www.esl-lounge.com/student/grammar/2g4-for-since-exercise.php
http://www.esl-lounge.com/student/grammar/2g23-finished-unfinished-time.php
http://www.esl-lounge.com/student/grammar/2g30-old-colonel.php