socialismo

The suffix does the work, exactly as it does in kapitalismo. -Ismo names a doctrine, a system or a movement, and its partner -ist- names the person who holds to it, so socialisto stands to socialismo as kapitalisto stands to kapitalismo. Neither ending is native Esperanto in the way -ej- or -ul- is. Both arrived whole from the European vocabulary and behave here exactly as they behave in every other language you know, which is the reason a page of political Esperanto is readable before you have learned any of the politics.

Watch the middle of the word. Esperanto's own root for of society is socia, and the welfare-and-policy adjective you already have at rank 1,952 is sociala. Neither is what sits inside socialismo: the word was borrowed in one piece from French socialisme, so it keeps the social- of its source. Do not try to rebuild it as socia plus -ismo - sociismo is not a word anybody writes.

Encyclopedic vocabulary, and it belongs in factual sentences. It sits beside politiko, ekonomio and partio, and beside the other -ismo words this part of the course carries: komunismo, faŝismo, nacionalismo and, closer to home, Esperantismo. Esperanto's own movement has argued about the last of those for a century, and the shape of the argument is in Esperanto hodiaŭ.