Why is there a question mark here?

[Rusty]

Repeating the statement and changing intonation is the common way to express surprise/disbelief in what you just heard. We do not ask, "The car is red?" without having heard that it is.

[AngelicaDeAlquezar]

Of course. What I had in mind was that a few years ago, most people I communicated with online inverted the verbs when asking a question, but lately, they tend to ask only with the question mark.

[Rusty]

None of the sentences in the original post is a question, of course, but as everyone has stated, it appears that when we are surprised or don't believe something we just heard, we allow the non-inverted subject/verb combination and change our intonation in order to elicit a response to our surprise or disbelief. This seems to change the statement into a question, hence the addition of the question mark.

If someone refused to eat pancakes, it would be very common to say, in disbelief, "You don't like pancakes?" This is, as poli stated, the same as asking, "Don't you like pancakes?"

[AngelicaDeAlquezar]

I see, thank you both! :-)

[reverser]

Ha, remember in the movie "My Cousin Vinnie" Ralph Macchio uses only intonation, meaning to ask the question "Are you saying I killed the clerk?" but says, "I killed the clerk?" That is taken as a confession. Hilarity ensues.