https://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/comparison_adjectives_easy.htm

https://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjective_comparison.htm

https://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjective_comparison2.htm

https://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/comparative_sentences.htm

https://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjectives_comparison_as_as.htm