numbers

http://www.oup.com/elt/global/products/headway/beginner/b_vocabulary/vocabularyunit01/hwy_begin_unit01_4/

a/an

http://www.englishexercises.org/makeagame/viewgame.asp?id=1971

a/an

http://www.ego4u.com/en/cram-up/grammar/nouns/exercises

a/an

http://www.members.iinet.net.au/~adelegc/grammar/articles/articles1.html

questions

http://www.oup.com/elt/global/products/headway/beginner/a_grammar/grammarunit01/hwy_begin_unit01_3/

questions

http://www.oup.com/elt/global/products/headway/beginner/a_grammar/grammarunit02/hwy_begin_unit02_2/

questions

http://www.hseidensticker.de/unit0/rogra1.htm

questions

http://www.aula21.net/segunda/juandiaz/ejercicio8.htm

questions

http://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-4438.php

plural of nouns

http://www.englisch-hilfen.de/en/exercises/nouns_articles/plural.htm

plural of nouns

http://www.members.iinet.net.au/~adelegc/grammar/plurals/plurals1.html

plural of nouns

http://www.roythezebra.com/reading-games/singular-or-plural-2.html

plural of nouns

http://www.roythezebra.com/reading-games/singular-or-plural-1.html

plural of nouns

http://www.1-language.com/englishcourse/unit11_grammar_exs2.htm

possessive adjectives: my, his, her, our

http://pagesperso-orange.fr/michel.barbot/hotpot/adj_poss/poss1.htm

possessive adjectives: my, his, her, our

http://eolf.univ-fcomte.fr/uploads/ressources/grammar/01_adjectives/01b_possessive_adj/01.htm

possessive adjectives: my, his, her, our

http://pagesperso-orange.fr/michel.barbot/hotpot/adj_poss/poss1.htm

countries and nationalities

http://iteslj.org/v/e/ab-countries_nationalities.html

countries and nationalities

http://www.inglesmundial.com/I1/vocabulary.htm

countries and nationalities

http://www.manythings.org/wbg/nationalities-jw.html