The boy is lying on a bed is cobsidered wrong... Hmm, even gramatically so? Or more a convention, the notion that the boy is at the end, new info, so therefore he is LIKELY the unknown one? What about "The boy is lying on THE bed"? Will this be accepted... (I am quite confounded at this juncture)...
I put "on the bed is a lying boy." Where did I go wrong on this? I feel that this should be accepted. When I go to learn another language I also try to learn how things are expressed in that language and make my translations fit the target rather than making the target fit my native language. All that said I could still be wrong but I feel that that should be a proper translation?
Languages don't always allow for 100% direct translations, especially when talking about word order in sentences.
"On the bed is a lying boy" doesn't really follow common English word order. Furthermore, the "is" in "is lying" is an example of an auxiliary verb that directly modifies "lying" to show tense. As I read your sentence, I get the sense that the boy on the bed is dishonest (while the sentence is trying to convey that he's actually physically situated on the bed in a specific posture).