Only one (A biologist looks at human language).

When we look at the languages of the world, they may seem bewilderingly diverse. From the point of view of communication systems more generally, however, they are remarkably similar to one another.

The words themselves are structured from a small inventory of sounds basic to the language, individually meaningless elements combined according to a system completely independent of the way words combine into phrases and sentences.

And the principles governing these systems of sounds, words and meanings are largely common across languages, with only limited possibilities for difference.

As the 11th edition of the Encyclopedia Britannica put it, “[...] all existing human speech is one in the essential characteristics which we have thus far noted or shall hereafter have to consider, even as humanity is one in its distinction from the lower animals; the differences are in nonessentials.”

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