catalyst for language evolution

What is a catalyst for language evolution? What can be serve as such a thing for English in the approaching years?

There doesn't need to be a catalyst. All languages naturally evolve over time. English is probably the language most resistant to change at the moment, due to it's prestige as the global language, and the fact that it's grammar is relatively simple and therefore much more impervious to change than say Latin ever was with it's myriad of different cases, declensions, etc.

If Hollywood decided to change their dialect, that would be about the strongest catalyst possible for changing English, don't you think? Of course it won't happen, but it could in theory...

"English is probably the language most resistant to change at the moment"

Excuse me, but how do you know?

Can I presume you understand and actively observe every language in the world so that you can make such a sweeping statement?

Learn Old English, than you can see the catalysis!