Esperanto · Chapter 28 · Lesson 21 · Themed review
La cxielo kaj la scienco
Star, moon, planet, atom. The words of the sky and the laboratory, and the international roots that make Esperanto's scientific register read like every other language's.
Practise this lesson
12-word session
A quick mix of exercises - recognise, recall, type and build each word. Miss one and it comes back round until it sticks.
Worth knowing
Fiziko, kemio, biologio: the words you already knew
Here is a small confidence trick. Look up at the night sky and you meet the plain Esperanto words - star, moon, sun, sky. Short, blunt, learned in an afternoon. Now walk into a laboratory and the vocabulary changes character entirely: physics, chemistry, biology, energy, , . You have not studied these. You already know them. A French, German, Polish or English speaker reads that second list and recognises nearly every stem, because those stems were never Esperanto's private property. They are the shared learned vocabulary of Europe, borrowed wholesale into the language on purpose.
Why the sky splits in two
The everyday sky is native and simple. , , , are the words a child needs, so Zamenhof kept them plain and root-like. The studied sky is international. When Esperanto reaches for science, matter, element, species, it stops inventing and simply takes the term the physicists of half a dozen countries were already using. This is a deliberate design choice, not a coincidence. In exactly the domains where the vocabulary was already international, Esperanto adopted it rather than manufacture a home-grown rival nobody would recognise.
The endings do the tidying
What Esperanto adds is regularity. The international stems arrive slightly different in each language; the endings iron them flat. A field of study takes -ik-o: . A science takes -i-o: , . You get -om-o in , -ent-o in and . The stem is borrowed; the ending is Esperanto's, and it never changes its job. So is an experiment, and you already knew that, and the -o merely tells you it is a noun. You are not memorising these words. You are recognising them and letting the grammar label them.
Put it together
. - The sun is a star.
. - Physics and chemistry are sciences.
. - The experiment showed a new element.
. - Every planet consists of matter and energy.
