Just that. Would everyone recognize when a question was asked with rising inflection at the end? How widespread is this understood among different languages?
There are many counterexamples, e.g. (I’m pretty sure) Basque, so it is not universal by any means.
It varies widely among languages. The Wikipedia article on Intonation has some examples.
This question is especially interesting in the context of tonal languages - where the pitch and change in pitch (contour) with which sounds are spoken is an integral part of the way a word is pronounced. The most well know example is Chinese, which knows four tones - flat, rising, falling-rising and falling. However, there are many other languages and tonal systems.
According to the answer to this question on the linguistics stackexchange
even for many of these languages, a rising inflection can be observed. There are also noted counter-examples.
Like once, at bandcamp?
How about is it universal in all Indo-European languages? Could it date back to PIE?
I can’t help but note one extremely annoying trait of some Australian accents of the last few of decades, where the rising inflection is placed on every sentence. It is particularly present in what we class as Bogan accents. (He says, with nose firmly held high.)
I’ve heard it, but - and this is just an observation - only from women. Apparently it’s also called UpTalk. Undoubtedly a learned characteristic.
Thanks. Great place to start looking further into this.
I assumed there would be exceptions. So what intonation would a Basque speaker use when asking a question, if any?
More information that is useful. Thank you.
I got to pondering this question because I’ve been watching a lot of undubbed Godzilla movies and the new Shogun mini-series. They have subtitles but I noticed without looking at the subtitles I can get a fairly good sense of a conversation sometimes. Barely an individual word that I recognize, yet something useful about the conversation comes across. And questions are detectable. Not quite as easily as in English, but there’s clearly something about the way they are spoken that I can pick up on.
Thai is a tonal language. So altering a word to have “rising inflection” normally just yields a different word. However the rising==question seems built in to some words!
/mai/ with a falling tone means “not” but /mai/ with a rising tone is added to a sentence to make it a question. And despite very different spelling and pronunciation, wiktionary implies that the latter word is derived eymologically from the former.
Women append the particle /kha/ to sentences to show politeness. But that particle has at least two forms: a falling tone is used to show agreement; common tone to show doubt or ask a question.
The word for “near” is the same as the word for “far” except that it has a falling tone.
This source states that information-seeking yes/no questions in Basque end in a falling or rising-falling circumflex contour. This link concerning question sentences appears to say the intonation is usually falling but can vary in specific varieties of Basque, sometimes changing to rising or mid-rising, but the presentation itself is not visible in my browser for some reason.
It would be better to seek clarification from posters on this board who are actually fluent in Basque 
Unclear how it arose. But insecurity resulting in every sentence sounding like a question is a possibility.
Be aware, by the way, that only certain types of questions end with a rising intonation in English, for instance yes/no questions. Questions about a choice often have a rising then falling intonation. For example, “Do you want the beef or the chicken for dinner?”
On the show On Patrol Live, whenever they are in CA it sounds like every single Hispanic male speaks this way. The cops included.
What’s kind of amazing is that some of our basic assumptions about universals in human communications aren’t. Even something as ingrained to most of us as nodding the head for yes and shaking for no isn’t universal.