Comparisons

You can read some explanations of how to make comparisons in English:

http://www.englisch-hilfen.de/en/grammar/adjektive_steig.htm

Then, you can practise:
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjective_comparison.htm
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjective_comparison2.htm
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjective_comparison3.htm
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjectives_comparison_sentences.htm
http://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjectives_comparison_sentences2.htm