Jaka jest różnica między ① What seems to be the problem ? i ② What does it seem to be the problem ? ?Możesz podać przykładowe zdania.

② is not correct, because the question word "what" should be replacing "it" in whatever your question is, but you have both "what" and "it" in the question, which are contradicting each other ("what" means you don't know what it is, but "it" means you do know what it is).

In general, to form a question in English, you need to take the statement form, and replace whatever bit you don't know with the question word, and then you need to find the appropriate way to move the question word to the front of the sentence. That second part is why a lot of questions use things like "what does ..." (because "do"/"does"/etc can be used to rearrange the order of words in the sentence so that the question word is first).

However, in this case, the statement you're starting with would be:

"(that thing) seems to be the problem."

So if we replace "(that thing)" with "what" (to make it a question) we get:

"What seems to be the problem?"

And in this case, we're just lucky because the question word ("what") is *already* at the front of the sentence, so we don't have to do anything else to it. It's already a correct question!

However, you could also start with the statement the other way around:

"The problem seems to be (that thing)."

So let's replace "(that thing)" with "what" again.. we get:

"The problem seems to be what?"

In this case, this isn't a correct question yet, because we need to move "what" to the front. This is where "does" is useful, because we can do this by saying:

"What does the problem seem to be?"

(which is actually also a valid way to ask basically the same question)

I hope this was helpful..