Sentence:  In the first case X^2-2, the minimum polynomial of \sqrt 2, <WSD>splits</WSD> completely over \Q(\sqrt 2); in the second case we see that X^3-2, the minimum polynomial of 3\sqrt 2, does not <WSD>split</WSD> completely over \Q(3\sqrt 2). 
Meaning of the word marked with <WSD> tags:  To factor into linear factors.