"The world is changing all the time."
Translation:Verden forandrer seg hele tiden.
You need the reflexive together with forandre in this sentence.
Verden forandrer seg alltid = The world is always (and inevitably) changing ("alltid" is not the same as "all time" even though the words match one for one).
Without the reflexive it needs to be a passive verb, although that alters the meaning: Verden forandres hele tiden. That suggests it's of an active influence by someone else (the world being the passive part) and not something the world is capable of on it's own. (The world is being changed all the time)