It was a simpler time. A friend introduced us, pulling up a static yellow webpage using a shaky dial-up modem. A man stood forth, dressed in a dapper black pinstriped suit with a red-accented tie. He held one hand out, as if carrying an imaginary waiter's tray. He looked regal and confident and eminently at my service.

Buffy the Vampire Slayer was the first show on American television to use the word "Google" as a transitive verb. It was 2002, in the fourth episode of the show's seventh and final season. Buffy, Willow, Xander and the gang are trying to help Cassie, a high school student who cryptically says she's going to die next week. In Buffy's dining room, they search through hard copies of Cassie's medical records and find nothing noteworthy. Willow, tapping away on a thick white iBook, turns to Buffy and asks, "Have you Googled her yet?"

As human beings, we use our voices for conversation. When we interact with voice interfaces, therefore, our natural instinct is to apply the same rules that we would to a human conversation. We expect to be understood, but more than this, we expect the entity we're conversing with to remember the history of our conversation and understand the context of any following remarks. For some time, major search companies like Google and Bing have worked to teach their search engines to understand queries in natural language. Natural language search queries are queries that sound natural spoken aloud, such as, "How high is the Empire State building?" They often begin with question words ("When…?" "How…?" "Why…?"), contain stop words ("a", "the", "of", "for") and full sentences.