I don't understand why it is feminine
Since the English sentence contains no information about the gender of the person it's addressed to, it can be translated into Hindi using either gender.
why is तुम बहुत छोटा हो wrong?
तुम and आप are grammatically plural, even though that can be either singular or plural in meaning.
तुम बहुत छोटा हो should also be an accepted answer
I think it should be plural.so instead of "chota" write it as "chote"
Why "तू बहुत छोटा है" is unaccepted?
Would another acceptable answer have been tum bahut chotai ho?
Can we use आप as part of this sentence ?