Skal have describes the course of things, whereas skal få is a change of course.
Han skal have nye tænder i næste uge, firmaet betaler. (He is going to have new teeth next week - his firm will pay.) Course of things
Du skal få dine nye tænder i næste uge. (I promise: you´ll have your new teeth next week.) Change of course
Tandlægen mener, jeg snart skal have nye tænder. (The dentist says I'll need new teeth soon.) Course of things
Jeg synes, du skulle få nye tænder. (Please consider getting new teeth!) Change of Course
Ifølge kontrakten med kommunen, skal skolen have flere elever næste år. (According to the contract the school is going to have more students next year) Course of things
Borgmesteren lover, at skolen skal få flere elever næste år. (The mayor promisses more students next year) Change of course
Vi har lavet et reklamespot, for at skolen skal få flere elever næste år. (We´re running an add on tv in order to get more students next year) Change of course
Lægen siger, at Peter skal have et titansøm i benet, indtil det er helet. (The surgeon says Peter'll have a titanium nail in his leg untill the fracture has healed.) Course of things
Kan du ikke tage sko på? Jeg er bange for, at du skal få et søm i foden. (Please put on your shoes! You could get a nail up your foot) (Change of course - and foot)