Questions & Answers about Учитель и студент дома.
Why isn't there a word for "are" in this sentence?
In Russian, the present tense of the verb "to be" is almost always skipped. You just state the subjects and their location, which literally translates to "Teacher and student at home."
Since the current lesson is about кто and что, how would I ask "Who is at home?" based on this sentence?
You use Кто (Who) because a teacher and a student are people. The question is simply Кто дома?. You only use что (what) for things that aren't people or animals.
I learned that the word for "house" is дом. Why does this sentence use дома?
дом is the noun for a physical house or building. The word дома is a location word (an adverb) that specifically means "at home." You use it whenever you want to say that someone is currently in their home.
If I ask Кто дома?, does the question word Кто change because there are two people (the teacher and the student)?
No, Кто never changes form just because you expect a plural answer. You ask Кто дома? (Who is at home?) whether you expect the answer to be one person or a whole group of people.