going to

http://www.kico4u.de/english/uebungen/5klasse/goingto2.htm

comparatives

http://pagesperso-orange.fr/raud.dugal/beginners/comparison/exercise%202.htm

comparatives: as/than

http://eolf.univ-fcomte.fr/uploads/ressources/grammar/02_comparatives_superlatives/02b_compartives_superlatives/12.htm

Adjectives/Adverbs: comparatives

http://personales.com/espana/malaga/englishhere/paginas/hotpotatoeswebpages/paginas/FILLCOMPARATIVE1.htm

Past Simple/Present Perfect

http://www.better-english.com/grammar/pspp1.htm

Simple Past or Present Perfect

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

since/for

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

Questions in present Perfect

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

present perfect negative statements

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

Present Perfect

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

Past continuous and past Simple

http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_progressive2.htm

Past simple and Past continuous

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

Past continuous, questions

http://www.englisch-hilfen.de/en/exercises/tenses/past_progressive_mix2.htm

Past Continuous

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

Simple past irregular verbs. negative sentences

http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_negation_sentences3.htm

Simple past, irregular verbs, negative sentences

http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_negation_sentences2.htm

simple past negative sentences

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

Simple past

http://www.englisch-hilfen.de/en/exercises/tenses/simple_past_statements2.htm

Past Simple

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

Present simple or continuous

http://www.englisch-hilfen.de/en/complex_tests/simple_present_progressive1/index.php

Present Simple or continuous

http://www.tolearnenglish.com/exercises/exercise-english-1/exercise-english-879.php

Present Continuous

http://www.ego4u.com/en/cram-up/grammar/present-progressive/form/exercises?form02

Present Continuous

http://www.oup.com/elt/global/products/headway/beginner/a_grammar/grammarunit13/hwy_begin_unit13_2/

Present Continuous

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-6414.php

present continuous

http://www.pumpkinandcompany.com/PAC/Kids-activ-games_Gquiz_Prsntcont1-5e.htm

Present Simple possitive statements.

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-4950.php

Present Simple: negation of sentences

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

Present Simple

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-9445.php

Present Simple

http://www.ego4u.com/en/cram-up/grammar/simple-present/form/exercises?03