SOMEBODY / ANYBODY / NOBODY

https://www.internationalschooltutors.de/English/activities/grammar/poly/218.html

INDEFINITE PRONOUNS

https://test-english.com/grammar-points/a2/something-anything-nothing-etc/

SOMETHING /SOMEBODY

https://agendaweb.org/exercises/grammar/somebody-something-somewhere.htm

SOMETHING / ANYTHING

https://agendaweb.org/exercises/grammar/indefinite/something-anything-1.htm

NOTHING

https://agendaweb.org/exercises/grammar/anything-something.htm

SOMEBODY, ANYBODY

https://agendaweb.org/exercises/grammar/somebody-anybody-nobody.htm