Why is there a question mark here?

[AngelicaDeAlquezar]

I have seen many native English speakers end what I understand as a statement or a command with a question mark.

Examples:

- I thought you didn't like pancakes
- I wonder if John is coming at all
- Guess who got the prize in the competition


My question is: although there are certainly implicit questions in these sentences, grammatically they don't look to me as actual questions. Is it accepted to write a question mark to them or is it just a common mistake?

[poli]

It's a common mistake.

[AngelicaDeAlquezar]

Thank you, Poli.

[Glen]

poli is right of course, and I would just like to mention the same phenomenon has been occurring recently in spoken language: that irritating - to my ears at least - "uptalk" wherein the final word of a declarative sentence is spoken with a rising tone of voice as though the sentence were a question. Here's hoping it's just a passing fad.

[poli]

Yes Glen, this fad, I fear, is here to stay. Some children and harebrained adults do this subconsciously to get other's attention. After all, when you make a statement but inflect it to sound like a question, others are more likely to listen being led to believe a response is required, so they are obliged to pay more attention. The down side is that the inflector may end up like the boy who cried wolf, and not get an answer when finally they ask a legitimate question.

[AngelicaDeAlquezar]

Hmm... that's even worse than I imagined. I don't have so much hearing practice... my English life is mostly writing-reading.

[poli]

It's part of an interesting phenomenon in the U.S. and probably Canada. It's Valley. Valley is a standard accent that sounds the same from New York to Los Angeles. There is very little regional variance. It is primarily spoken by young people of average intelligence from well-to-do families who are likely to have gone to college. It is more frequently used by women than men. The question-when-it's-not-a-question is part of it. More recently a gruffer vocal fry has been incorporated in Valley Talk. Vocal fry is the hoarse voice heard by very ill people or those who use heroin (which is why heroin is known as the hoarse), but for the new users of vocal fry, it's an affectation rather than an affliction.

Though grating, I think Valley is a fascinating trend. It's an accent based more on class, gender and intellect than region.

[Julvenzor]

In many languages it's theintonation which indicates if a sentence is affirmative or interrogative. Can it be a new tendency to avoid the inversion of the word order?

PS: 'Vocal fry' has no forgiveness.

[AngelicaDeAlquezar]

@Julvenzor: I see more and more people avoiding the inversion of the verb when making questions and relying on the intonation and the question mark, rather than on grammar.

@Poli: Ah, yes, I've seen a few videos with people speaking as if they were asking questions all the time, and making strange acute emphases on sentences, where I wouldn't expect them.

[poli]

You may know this, but in English the intonation you write about is acceptable. Example: The car is red. The car is red? I thought it was orange.
The car is red?, is a perfectly good alternative to, is the car red?