How Esperanto Works

One of the cornerstone ideas behind Esperanto is that one needn’t have a separate word for every possible noun, verb, and adjective in human language, but can build an infinite number of words from just a small number of roots and affixes, mixing and matching them like Lego bricks.

For example, from the root bel- (“beautiful”):

The Lego-ness of the language is such that the derivational affixes themselves (the yellow and green bricks in the example above) are often used as separate words, much like “ism” is in English:

This makes word-building on the fly a fairly simple matter — but not always a simple as it seems. For example, consider the root paf- (“shoot”):

One would surmise from this that -o names the action, -ad- prolongs the action, and -il- names the instrument. But now look at klab- (“bludgeon”):

Why does klabo name the instrument, you might ask, and not klabilo? If klabado indicates prolonged or repeated action, what’s the suffix for a single strike with a klabo?

The reason for the different treatment of paf- and klab- is that klab- is by default a noun root referring to the instrument, whereas paf- is by default a verb root referring to the action. One can make klab- a verb by changing -o to -i, but one can’t make the action of klabi into a noun by changing the -i back to -o; one must preserve the “verbness” by adding a verbal suffix.

The suffix -ad-, which indicates repetitive action, is the only such suffix available in Esperanto; for a single stroke of a klabo, one must make a compound word like klabofrapo “a club-strike”. (Someone once proposed -im- to indicate a single action, as in martelimo “a hammer strike”, but that seems to have never caught on.)

The importance of knowing to which grammatical class a root belongs applies to all words in Esperanto, not just the odd one here and there. Unfortunately, a root’s grammatical class is rarely obvious; for that, the novice will need a dictionary before the mixing and matching can begin.

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