My phone is not rooted

I use a sd card

and as the phone has 11gb itself this is enough for me as i used it for apps music and pictures

now as i got it the sd card i want to keep all my apps on the usb storage(internal memory)

and i will keep the rest like music,pictures on the sd card

but i even realized that some apps go to the internal memory thats 2gb

My question is, how can i make it default for apps downloaded to be saved to usb storage, and how can i prevent them going to internal memory?