PRESENT PERFECT SIMPLE VS PRESENT PERFECT CONTINUOUS

http://www.englishpage.com/verbpage/verbs7.htm

http://www.englishpage.com/verbpage/verbs8.htm

http://www.perfect-english-grammar.com/present-perfect-present-perfect-continuous-1.html

http://www.perfect-english-grammar.com/present-perfect-present-perfect-continuous-2.html

http://www.perfect-english-grammar.com/present-perfect-present-perfect-continuous-3.html

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex02

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex03

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex04

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex05

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex06

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex07

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex08

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex09

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex10

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/exercises?ex11

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/tests?test1

https://www.ego4u.com/en/cram-up/grammar/prepersim-preperpro/tests?test2

http://esl.fis.edu/grammar/multi/ppsppc.htm

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-30523.php

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

http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive2.htm

http://www.englisch-hilfen.de/en/exercises/tenses/simple_present_progressive3.htm

http://www.autoenglish.org/gr.percon.i.htm