The Fastest, Most Effective Way to Discourage Someone
That's telling a person something they're struggling to learn or do is easy.
Sure, it might be easy for you but it isn't for them. If it was easy, they wouldn't be struggling, would they?
Telling a person that something with which they're struggling is easy makes them feel inadequate. It makes them feel inferior. Frankly, it makes them feel stupid.
Whenever you come across someone who's struggling like that, don't tell them that what they're trying to do is easy. Instead, find out why they're struggling. Offer what advice you can or point them to a person or a resource that can actually help them.