  Recent years have seen significant market penetration for voice-based
personal assistants such as Apple's Siri. However, despite this success, user
take-up is frustratingly low. This position paper argues that there is a
habitability gap caused by the inevitable mismatch between the capabilities and
expectations of human users and the features and benefits provided by
contemporary technology. Suggestions are made as to how such problems might be
mitigated, but a more worrisome question emerges: "is spoken language
all-or-nothing"? The answer, based on contemporary views on the special nature
of (spoken) language, is that there may indeed be a fundamental limit to the
interaction that can take place between mismatched interlocutors (such as
humans and machines). However, it is concluded that interactions between native
and non-native speakers, or between adults and children, or even between humans
and dogs, might provide critical inspiration for the design of future
speech-based human-machine interaction.
