@shady_arc! Of course, you can say somebody is a funny person in English! Just have a look at newspaper articles, books, TV, blogs online. People use it all the time!
Just some examples to convince you! Here the Rollingstone vote for the 50 funniest peopleThe http://www.rollingstone.com/culture/lists/the-50-funniest-people-now-20130124 Here for instance is an English podcast about describing a funny person-: https://www.youtube.com/watch?v=7JNRHj8RdA8
Interesting topic. I am not sure if you are hoping to collect more feedback, but I can offer some insight as well (native English speaker and teacher). I agree with the previous person who wrote that "a funny person" can certainly be used in a sentence. And while I do not speak for every native English speaker, we rarely use the phrase "cheerful person" in casual conversation.
It's not incorrect, it's just not common. If I want to say that I believe someone is "cheerful" or "positive" I might be more inclined to use the word "positive." For example, "They're a really positive person, don't you think?" There are also phrases such as "upbeat person, crowd pleaser, and people-person" as well. All of these will imply the same thing to an average English speaker.
I apologize for the quotation marks. I was just trying to isolate the examples.
By the way, the Ukrainian course is my favorite duolingo course thus far. One day I will pick up the German and Danish courses again, but for now I am content to be a little monogamous.
I am from the Russian course, not the Ukrainian one. It is just that Russian native speakers tend to misunderstand the relation between "весёлый" and "funny", too. If your friend is positive and upbeat, you can call them "fun" but calling a person "funny" means something different.