Grammar exercises

1.       Present Perfect

http://www.learnenglish-online.com/grammar/tests/presentperfect.html

2.       Irregular verbs

http://www.perfect-english-grammar.com/irregular-verbs-exercise-2.html

3.       Adverbs

http://www.ego4u.com/en/cram-up/grammar/adjectives-adverbs/adverbs/exercises

                                                                                                                                                                    4.  Cause and effect

http://teacher.scholastic.com/lessonrepro/reproducibles/litplace/r980217e.htm