Just a question, should it really allow "Lubi zwierzęty" (it did for me, but suggested the 'alternative' answer was "on lubi zwierzęta" - which is obviously correct).
Great work - really enjoying this btw.
Words ending in -ę get -ęta in plural (unless they end in -mię, in which case it turns into -miona).
All -ę words are neuter, and neuter words tend to get -a in plural.
zwierzęty is not a word, it should not be accepted.
Neuter nouns ending in -ę often (always?) refer to animals in some way, and their plural forms do take -eta: zwierzę - zwieręta; piskię - piskięta; niemowię - niemowięta
Why lubi and not another "like" variant?
(simple question, but these discussions are perfect for revising concepts, rather than searching back through old exercises :)
"lubi" is the 3rd person singular form, so exactly "he/she/it likes".