In my observation, Quin will pick up new things very quickly if the motivation and the method  used are the correct ones.

If only all things were as easy to teach her as the ones she learns without any prompting by me:(  

We live on two acres in the desert and some people let their dogs run or they get out or whatever the excuse is,  but if they come over to my house and up to my door Quin will bark just like if there is a coyote well maybe she barks more ferociously at the coyotes:) but anyway when she barks at the dogs I open the dog and yell "Shooo go home"  and they run home and I close the door and tell her she is a good dog.  This has only happened a couple of times. But today I was making the bed and she and the cat were laying on it and so as I am shaking the sheet I say "Shoo go on" and right away she starts barking like there is something outside and she runs to the window (unlike the cat who continued to just lay there ha ha)  I didn't figure it out right away but then it dawned  on me what I had just said and I laughed to my self and decided to test it.  I went out in the living room and said "shoo" and right away she starts barking and looking at me like where are they let me at em.  Ha ha  so now  I know that trigger. Being allowed to bark is a good motivator apparently!