[quote=whizzball1]
So I just learned that yes, no, and okay are words called pro-sentences: words that are grammatically considered full sentences, where the entire meaning of the sentence is derivable by context. So if you asked me "Is this true?" I would say "Yes," which would be a sentence with the same meaning as "It is true." I always thought they were interjections. They be seen as interjections, but they are their own part of speech.
[/quote]

Well the shortest sentence is "Go."