Polar interrogatives are usually articulated with forward body lean, head forward (chin down), raised, or lowered eyebrows, widened eyes, eye gaze directed to the addressee and a single or slightly repetitive head nod. Some of these non-manual markers are represented in the example below.
bl-f
ht-f
re
hn
understand ฤฑx2
โDo you understand?โ
In a relatively longer question, the spreading domain of these different non-manual markers may differ. Head forward and raised eyebrows tend to spread over the entire question whereas repetitive head nod tends to occur at the end of the question, usually spreading only over the predicate and the sign(s) following it, for instance, the question particle or a subject pronoun.
When a polar interrogative is negated, this creates a potential conflict between head forward (chin down) which marks the polar interrogative and backward head tilt which marks negation. In those cases, even though the question starts with head forward, this non-manual marker is replaced with (a single) backward head tilt when the predicate and the negative sign not are articulated.
h-f ht-b
re
adana ever go^not
โHavenโt you ever been to Adana?โ
(Dikyuva et al., 2015: 273)
In the following sections, the non-manual markers are provided in the examples only if they are crucial to the description of the topic.