Shouldn't be kindergarden?
According to English Wiktionary, 'kindergarden' is a misspelling of 'kindergarten'. The word is a borrowing from German and came to English as a whole, without changing.
Agreed. "Kindergarten" is the standard English word.
Kto pracuje w tej zerówce?
I do not understand, ta przedszkoła is a female gender, why - w tym przedszkolu?
It's przedszkole and it's neuter.
przedszkole neuter and szkoła feminine . Try to find the logic !!!!
It's easy, look at the endings. -e means it's neuter and -a that it's feminine. Putting exceptions aside, of course.