Bobaljik & Wurmband (2015) have recently developed a hypothesis that no language truly mixes wh-movement and wh-in-situ structures in its syntax, with seemingly optional wh-in-situ in a wh-movement language being analyzed as a question with declarative syntax. In this paper, we will present novel data from Colloquial Singapore English (CSE) which question this hypothesis. Instead of assuming that the Q-feature of the interrogative CWH head in a language must be specified in a binary manner (valued or unvalued), we will propose that this feature is underspecified in languages such as CSE. The proposed amendment is not only sufficiently restrictive to cover the type of languages predicted by B&W’s original hypothesis, but also flexible enough to accommodate languages with a mixed wh-system. We will further argue that contact-based explanations, though plausible, do not have to be taken as a reason for CSE to develop this specific trait, which could have developed under independent, non-contact situations. This position is supported by Malay and Ancash Quechua, two non-contact languages which nonetheless exhibit optional wh-in-situ like CSE.