strong negation

[rezaa]

which one is stronger and why
- it never ends
- it doesn't end
thanx in advance

[Anglika]

Perhaps you can put these into sentences to show us how you want to use them?

[rezaa]

although i dont think strong negation has to do with the context, i think using an adverb or an auxilary that's what really matters. and i'd like to know why? specially if it has to do with transferred negation. anyway, here's an extract from the internet:
From Lori Coolican, The StarPhoenix :Some said the Martensville nightmare was finally over when the provincial government announced in March that it had reached out-of-court settlements in the final two malicious prosecution lawsuits filed by the wrongly accused. Try telling that to Ron Sterling. “It doesn’t end. It never ends. It will never end,” Sterling said in a recent interview.”Even if we have a public inquiry, it won’t end. But if you want to print any statement from me at all, you can print that I demand a public inquiry into what was done. I’ll want a public inquiry until I’m dead. But do you think we’ll get one? Not.”

[Tdol]

It really depends on the context. In your example, the sentences with 'never' are stronger, but if it were simply in a description of a process that has no end, then the use of 'never' would not necessarily be more emphatic.