Cuando una pregunta utiliza la palabra "usted"

[laepelba]

I am using a purchased software package to learn Spanish. I feel like I am learning a LOT! One thing that I have not been able to follow is the use of the word "usted" in a question. For example, sometimes they will state the question like this: "¿Cuándo escribe usted?" or "¿Dónde lee usted?" And other times they will state the question like this: "¿Usted cuándo escribe?" or "¿Usted dónde escribe?"

Is there a difference? Because I have been getting questions wrong (which is very upsetting for a perfectionist like me!) and I am frustrated because it seems like the two constructions have been used interchangeably.

If there is a difference, what is that difference? How do I know when to put the "usted" at the beginning of the sentence, and how do I know when to put it elsewhere?

¡Muchas gracias por su respuesta en inglés!