Forms 6a,c1,c2. Plurals. Countable and uncountable nouns

For practicing plurals:
https://www.englisch-hilfen.de/en/exercises/nouns_articles/plural6.htm;
https://www.englisch-hilfen.de/en/exercises/nouns_articles/plural7.htm;
https://www.englisch-hilfen.de/en/exercises/nouns_articles/plural.htm.

For practicing countable and uncountable nouns:
https://www.englisch-hilfen.de/en/exercises/nouns_articles/countables.htm;
https://www.englisch-hilfen.de/en/exercises/nouns_articles/countables2.htm;
https://www.englisch-hilfen.de/en/exercises/nouns_articles/uncountable_nouns.htm.