The five basic position of Kung Fu, even if they look easy require so much strength and discipline to adapt your body to the movements. This discipline is about repetitions and because that this needs a lot of dedication, this positions will be in all your life of the Chinese martial arts. 

Du Li is one of the positions that is more hard in the first training it requires not only strength and discipline as I say in the paragraph up,  but also requires of balance. A straight position with a leg up with the foot defending the knee.

Ma bu planting the feet in the ground and the knees flexed in a 90 degrees angle, if you aren't used to a workout this is a total mutilation to your legs. 

Gong Bu is very look like Ma Bu with the detail that is to one of your sides, you have to have clear that you don't have to put your feet in the same line the one in the front must be a little bit to the outside, this way you don't loose the balance.

Xu bu in this position you leave all the weight of your body resting in the foot behind. 

 Pu bu is for the one that are flexible one of the positions easier because the body and your legs found a position were can rest, for me it was one of the easy ones. 

Even though this are not all the basic positions of Kung Fu this are the more necessary to start a good training and will help you with a great posture.