Exercises

https://agendaweb.org/exercises/grammar/plural/plural-y-write https://agendaweb.org/exercises/grammar/plural/irregular-plurals https://agendaweb.org/exercises/grammar/plural/irregular-plurals-write https://agendaweb.org/exercises/grammar/plural/regular-irregular-write-2 https://www.englishexercises.org/makeagame/viewgame.asp?id=723

Quizes

https://agendaweb.org/exercises/grammar/plural/regular-irregular-test-1 https://agendaweb.org/exercises/grammar/plural/regular-irregular-test-2 https://www.english-4u.de/en/grammar-quizzes/singular-plural.htm