1. He is a black and white dog.
2. It is a black and white dog.
3. She is a black and white dog.
(Are they all grammatical?)
Yes, all are fine.
Yes
Yes, all three sentences are grammatically correct.
In these sentences, "black and white" is used as an adjective phrase to describe the dog. Adjectives are words that modify or describe nouns. In this case, the phrase "black and white" describes the characteristics or appearance of the dog.
In sentence 1, "he" is used as the subject pronoun referring to a male dog.
In sentence 2, "it" is used as the subject pronoun referring to an animal (without specifying the gender).
In sentence 3, "she" is used as the subject pronoun referring to a female dog.
So, all three sentences are grammatically correct and convey the same meaning with a slight variation in terms of the gender of the dog being referred to.