Since we are talking about accuracy and efficiency of language here via a textual interface, I'll voice the following observation, and attempt to not be overly pedantic
The statement/question "Clearly you've never tried to learn a second language?" is an expression pattern I see frequently. A statement ended with a question mark.
Perhaps it was meant to be intentionally cheeky? Which would be funny, if I knew to interpret it that way. A /s would make this more obvious to me
Or possibly, the sentence was started based on an assumption. This was realized part way through, then a ? was tacked on at the end?
Is there another way to interpret this expression that I am not aware of?
Assumptions of others' knowledge seems to be commonplace, yet we seem to still convey ideas somewhat decently. "Rum and Coke" vs "Roman Coke". Maybe Roman's love their rum and Coke? Either way, odds are, I'll receive the correct drink.
In regards to the original article. Here are my assumptions.
I perceive a sentence as a train-of-connected-thoughts that conveys an actional expression of a person's experience, as well as their attached feelings to that experience. In that regard, I similarly view any attached grammar.
"The dog did a backflip?!" - A person receives data of an experience, first checks it's validity, realizes it falls outside their current understanding of possibility, then proceeds to double-check that they received the data correctly
> Receiver of data: "Wait, did I hear that correctly?"
"The dog did a backflip!?" - A person receives data of an experience, first accepts it (likely first-hand or from a reliable source), then realizes it falls outside their current understanding of possibility based on other reinforced models of reality, and proceeds to doubt said data)
> Receiver of data: "I didn't believe my own eyes!"
"The dog did a backflip‽" - A person doesn't have a preconceived notion for the data they are receiving, and has received it in a way that conveys that it is extraordinary - conveyed below
> Presenter of data: "The dog did a backflip!"
> Receiver of data: "Do dogs not usually do backflips?"
Feel free to correct me if I am wrong