"This is a difficult question."
Translation:Это сложный вопрос.
That seems like it would be actually wrong. I think you have to either do "Это сложный вопрос" - This is a difficult question. or "Этот вопрос - сложный" - This question is difficult or "Этот сложный вопрос" - This difficult question
All three only slightly different but definitely not interchangable