I was just thinking about two sentences: 1) A pig is a kind of animal. 2) A species is a kind of animal. However, you can't say "Pigs and species are both kinds of animals". Where exactly is the difference in meaning - in the word "kind", maybe, or in "is"? Are there any natlangs or conlangs in which these two sentences with nonparallel meanings wouldn't have parallel structure? Matt McLauchlin Montreal, Quebec, Canada English/franšais/esperanto/espa˝ol http://www.crosswinds.net/~montrealais "The fire is burning, the long night draws near, All who need comfort are welcome by here..." - The Wyrd Sisters, "Solstice Carole"