Beyond and behind can also be used as an adverb, as it tells you where, but not at the start of a sentence

Preposition. They are the worst because there are no grammar rules to help you, I recommend learning them one by one. It helps to study the word in a good dictionary, for example, "beyond". If you make a mistake with them it's not fatal because people will understand you.

Never. Q: What was beyond the kitchen?/What was it beyond the kitchen? (Let's just talk about the grammar, though I don't think beyond is quite appropriate here. ) A: (What was) beyond (as a preposition) the kitchen was the wash area./(What) beyond (as an adverb) the kitchen was the wash area. (The subject in this context is just omitted. )