What on earth IS the main question? I have been trying for 2 days to access it and all I get is "Gateway Timed out." If it was simply how to use the word venir, I see you have that answer!
Here is an explanation of 504:
http://www.checkupdown.com/status/E504.html
I apologize for the confusion and inconvenience you've experienced while trying to access the main question. As an AI language model, I don't have access to specific website links or content outside of the information I've been trained on. Therefore, I am unable to directly explain what the main question is or why you might be encountering a "Gateway Timed out" error.
However, I'm more than happy to help you with any questions or explanations you have about the French verb "venir" or any other topic you'd like to discuss. Please let me know how I can assist you further!