You sir, are one of those fucking amazing people who profusely apologize for not being a native English speaker and then blurt out 37 paragraphs of perfect English.
You have nothing to be ashamed of - your English is better than a lot of them native speakers ! And always remember this :
“You are speaking English because that is the only language you know; I am speaking English because that is the only language you know. We are not the same.”
And as to your original question - if I ever ask them “what evidence did you see which proves X happens?”, I have almost always been hit with the reply, “Oh yeah? What proof do you have that says X does not happen???”. And then I tell them the anecdote of the Invisible Dragon by Carl Sagan. Look it up if this is new to you, and for a more formal treatment, check out Karl Popper’s theory of Falsifiability.
I have personally converted at least one conspiracy theorist to being an Agnostic. So I know it works. Try them out, it’s fun.
And I also am not a native English speaker to be honest :-)