[Please stop shouting, I hear just fine.]
Simply put: Your tree is not getting nearly enough light.
One job of the leaves of your tree is to absorb light, In response to when there is not nearly enough of it
they become larger to provide as much surface area as possible with which to provide the plant with it's requirements.
You will find many articles of interest on these two pages, The ones re: beginners and basics will be very helpfull to you.
Please post a picture of it and tell us abit about the enviroment you keep it in as well as your habits wrt watering.