Polar interrogatives in Turkish Sign Language are marked with a special head movement, HEAD FORWARD. In this study I look at the distribution of this nonmanual marker in the embedded context and show that it is likely not merely a syntactic clause-typer as previously claimed in the literature. My findings reveal that this nonmanual marker's presence and lack thereof distinguish between the semantic types question and proposition, and that it differs from its wh-counterpart, the HEAD BACKWARD, in that it is the sole syntactic clause-typer of the interrogative type, i.e. single conjunct polar, that it marks.