PASSIVE VOICE
Present Simple
https://www.englisch-hilfen.de/en/exercises/active_passive/sentences_simple_present.htm
https://www.ego4u.com/en/cram-up/grammar/passive/exercises?simple-present-2
Past Simple
https://www.learnenglishfeelgood.com/passive-voice-simplepast1.html
https://www.ego4u.com/en/cram-up/grammar/passive/exercises?simple-past
Mixed Tenses
https://www.english-grammar.at/online_exercises/passive-voice/pa005-active-passive.htm
SUBJECT OBJECT QUESTIONS.
https://learnenglish.britishcouncil.org/beginner-grammar/question-forms-subjectobject-questions ( read the explanation first, and then do the exercises which are at the bottom of the page)
https://www.examenglish.com/grammar/A2_subject_and_object_questions.htm
https://elt.oup.com/student/result/engint/a_grammar/unit01/1b_2?cc=global&selLanguage=en
PRESENT PERFECT WITH ALREADY , YET, STILL ......
https://learnenglish.britishcouncil.org/intermediate-grammar/just-yet-still-already
http://www.esl-lounge.com/student/grammar/2g7-just-yet-
already.phphttp://www.servator.cat/servator_cat/eva/index_files/Grammar/2ndcycle/4tESO/prsperf2.htm
PRESENT PERFECT WITH SINCE AND FOR
https://www.ego4u.com/en/cram-up/vocabulary/since-for
https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-3647.php
PRESENT PERFECT vs SIMPLE PAST
https://www.englisch-hilfen.de/en/exercises/tenses/simple_past_present_perfect.htm
https://elt.oup.com/student/solutions/preint/grammar/grammar_05_022e?cc=global&selLanguage=en
https://www.ego4u.com/en/cram-up/grammar/simpas-preper/exercises?ex02
https://www.ego4u.com/en/cram-up/grammar/simpas-preper/exercises
PAST SIMPLE vs PAST CONTINUOUS
https://learnenglish.britishcouncil.org/beginner-grammar/past-continuous-and-past-simple ( the exercises are after the grammar point, at the bottom of the page)
https://www.ecenglish.com/learnenglish/lessons/past-simple-vs-past-continuous
https://elt.oup.com/student/project3rdedition/level5/unit1/grammar/exercise1?cc=global&selLanguage=en
MODALS
https://www.ecenglish.com/learnenglish/lessons/modal-verbs-1-permission-prohibition-obligation-no-obligation ( first the grammar point , then the exercise)
https://learnenglish.britishcouncil.org/intermediate-grammar/modals-1
https://elt.oup.com/student/solutions1stedition/ui_unit_page/unit7/grammar/exercise1?cc=us&selLanguage=en
