The majority of Esperanto speakers learn the language through self-directed study, online tutorials, and correspondence courses taught by volunteers. In more recent years, teaching websites like lernu! have become popular.
Esperanto instruction is occasionally available at schools, such as a pilot project involving four primary schools under the supervision of the University of Manchester, and by one count at 69 universities. However, outside of China and Hungary, these mostly involve informal arrangements rather than dedicated departments or state sponsorship. Eötvös Loránd University in Budapest had a department of Interlinguistics and Esperanto from 1966 to 2004, after which time instruction moved to vocational colleges; there are state examinations for Esperanto instructors.
Various educators have estimated that Esperanto can be learned in anywhere from one quarter to one twentieth the amount of time required for other languages. Some argue, however, that this is only true for native speakers of Western European languages. Claude Piron, a psychologist formerly at the University of Geneva and Chinese-English-Russian-Spanish translator for the United Nations, argued that Esperanto is far more "brain friendly" than many ethnic languages. "Esperanto relies entirely on innate reflexes [and] differs from all other languages in that you can always trust your natural tendency to generalize patterns. [...] The same neuropsychological law [— called by] Jean Piaget generalizing assimilation — applies to word formation as well as to grammar."
Four primary schools in Britain, with some 230 pupils, are currently following a course in "propedeutic Esperanto", under the supervision of the University of Manchester. That is, instruction in Esperanto to raise language awareness and accelerate subsequent learning of foreign languages. Several studies demonstrate that studying Esperanto before another foreign language speeds and improves learning the second language to a greater extent than other languages which have been investigated. This appears to be because learning subsequent foreign languages is easier than learning one's first, while the use of a grammatically simple and culturally flexible auxiliary language like Esperanto lessens the first-language learning hurdle. In one study, a group of European secondary school students studied Esperanto for one year, then French for three years, and ended up with a significantly better command of French than a control group, who studied French for all four years. Similar results were found when the course of study was reduced to two years, of which six months was spent learning Esperanto. Results are not yet available from a study in Australia to see if similar benefits would occur for learning East Asian languages, but the pupils taking Esperanto did better and enjoyed the subject more than those taking other languages.