"Who is driving the train?"
Translation:Treni kim sürüyor?
Those are correct. Another way to translate an infinitive is to say 'to verb', so in that example you could say “To give is better than to to receive,” and it means the same thing.
But there are -ing words in English where you cannot say 'to verb,' such as “you are coming”, “you are eating”, or, as in this sentence, “you are driving.” Those are gerunds. You can change the 'verbing' to 'to verb', but it sounds archaic and does not mean the same thing.
Hope that answers your question.