American sign language uses facial grammar. Facial expressions can be used as morphemes to mark (add information to) other signs. When used to add information to other signs facial expressions are considered to be non-manual markers (NMM).
In ASL we use a "WH-type question facial expression" when marking a sign or a phrase as a open ended question such as the questions created when you use signs that are commonly associated with question words that begin with the letters "WH" such as who,
what, when, where, why, which and/or similar concepts such as "how" when used as a question.
The "WH-question expression" generally consists of furrowing (or squinting) the eyebrows and sometimes cocking the head slightly as a way of emphsizing that you are asking a non-rhetorical, non-yes-or-no question:
Here is an example of "WH-question" facial expression in a frame grab from the sign "WHEN" being used as a question:
Notes:
Also see:
►
WH-questions in ASL
►
WH-question Placement in ASL
►
WH-rightward movement unnecessary in very short questions