Tones when asking questions
It seems like there are multiple languages where a normal statement can be turned into a question just by changing the tone at the end of the sentence.
He eats three apples a day. --> He eats three apples a day?
Er isst drei Äpfel am Tag.--> Er isst drei Äpfel am Tag?
Él come tres manzanas al día. --> Él come tres manzanas al día?
I was wondering if this is an official trend across many languages or not? Does this only apply to roman or germanic languages? Which languages does this not apply to, and how are question marks expressed in other languages? I brought this up to a friend of mine (that statements can be turned to questions without changing word order in many languages), but they thought I was oversimplifying it, and that there was no trend.
(Transferred from old LINGUIST List Ask-a-Linguist site)