Esperanto etymology

Zamenhof took most of his Esperanto root words from languages of the Italic and Germanic families, principally Italian, French, German, Yiddish, and English. A large number are what might be called common European international vocabulary, or generic Romance: Roots common to several languages, such as vir- "man", found in English words such as virile, and okul- "eye", found in oculist. Some appear to be compromises between the primary languages, such as tondri (to thunder), per French tonner, Italian tuonare, German donnern, and English thunder.

The Greek origin of the nominal inflections can be seen in the Greek a-declension nouns such as the word for "muse": musa, plural musai, accusative musan, which in Esperanto is muzo, muzoj, muzon. Greek o-declension words such as logos, logoi, logon (word) are similar, as are adjectival declensions such as aksia, aksiai, aksian (worthy). Greek was perhaps also the model of stressed i in Esperanto words like familío (family), which follows the common Greek pattern of aksía (worthy) and oikíai (houses).

Esperanto has a/i/o ablaut for present/past/future tense, which has partial parallels in Latin present amat, perfect amavit, and the corresponding infinitives amare, amavisse. Otto Jespersen said of the ablaut,

This play of vowels is not an original idea of Zamenhof's: -as, -is, -os are found for the three tenses of the infinitive in Faiguet's system of 1765; -a, -i, -o without a consonant are used like Z's -as, -is, -os by Rudelle (1858); Courtonne in 1885 had -am, -im, -om in the same values, and the similarity with Esperanto is here even more perfect than in the other projects, as -um corresponds to Z's -us. —An International Language (1928)

There may have been a Volapük influence as well, or the two languages may have shared a common influence from earlier languages. In Volapük, the vowels are present a-, future o-, past perfect i-, as well as imperfect ä- [ɛ]; Esperanto retained a distinction between preterite -is and imperfect -es until 1887, the year the modern form of the language was published.[6]

Jespersen didn't parse all of the morphology.[7] The ablaut for the five languages is as follows:

	Faiguet (1765)	Rudelle (1858)	Volapük (1880)	Courtonne (1885)	Esperanto (1887)
present	-a	-a	-a- [8]	-a-	-a-
future	-y [9]	-o	o-	-o-	-o-
past/preterite	-i	-i	i-	(i)[10]	-i-
imperfect	-e	-e	ɛ- [11]	-e-	old -e-
conditional		-ju [12]		-u-	-u-
subjunctive		-u [13]		-ə-	-u

The infinitive suffix -i may derive from Latin deponent verbs, such as loqui (to speak). With elements like these that are only one or two letters long, it is difficult to know whether resemblances are due to the forms being related, or just coincidence. For example, it is speculated that the jussive -u is from the Hebrew imperative -û, but it could also be from the Greek [u] imperative of deponent verbs such as dekhou (receive!); or perhaps it was inspired by [u] being found in both Hebrew and Greek. Similarly, adverbial -e is found in Latin and Italian (bene) as well as in Russian (after a palatalized consonant); the participle bases -t- and -nt- are found in Latin, Italian, Greek, and German; and the pronominal base -i is found in Italian (-mi, -ti, -vi, -si, -gli for Esperanto mi, ci, vi, si, li) and English (me, we, he, she).

Modern international vocabulary, much of it Latin or Greek in origin, is of course used as well, but frequently for a family of related words only the root will be borrowed directly, and the rest will be derived from it using Esperanto means of word formation. For example, the computer term 'bit' was borrowed directly as bito, but 'byte' was then derived by compounding bito with the numeral ok (eight), for the uniquely Esperanto word bitoko ('an octet of bits'). Although not a familiar form to speakers of European languages, the transparency of its formation is helpful to those who do not have this advantage. Moreover, even bito has the synonym duumo, based on du (two) and -um- (the affix with undefined meaning).

Esperanto has been used to discuss philosophical concepts by at least one author in the UK.[14]

With the exception of perhaps a hundred common or generic plant and animal names, Esperanto adopts the international binomial nomenclature of living organisms, using suitable orthography, and changing the nominal and adjectival grammatical endings to -o and -a. For example, the binomial for the guineafowl is Numida meleagris. In Esperanto, therefore, a numido would be any bird of the genus Numida, and a meleagra numido the helmeted guineafowl specifically. Likewise, a numidedo is any bird in the guineafowl family Numididæ.

There is some question over which inflection to use when assimilating Latin and Greek words. Zamenhof generally preferred the oblique stem over the nominative singular form, as in reĝo (king), which follows the Latin oblique forms with reg– (compare English regicide), or floro (flower) as in floral, rather than nominative singular rex and flos. However, European national standards differ in this regard, resulting in debate over the form of later "international" borrowings, such as whether the asteroid Pallas should be Palaso in Esperanto, parallel to French and English names Pallas, or Palado, as in Italian Pallade, Russian Паллада (Palláda), and the English adjective Palladian. In some cases there are three possibilities, as can be seen in the English noun helix (x = [ks]), its plural helices (c = [s]), and its adjective helical (c = [k]). Although the resulting potential for conflict is frequently criticized, it does present an opportunity to disambiguate what would otherwise be homonyms based on culturally specific and often fossilized metaphors. For example, Venuso (the planet Venus) may be distinguished from Venero (the goddess Venus), all three of the forms of Latin helix are found as Esperanto roots, one with the original meaning, and the other two representing old metaphors: helico (a spiral), heliko (a snail), helikso (the incurved rim of the ear).

Normally the Latin or Greek inflectional ending is replaced with the Esperanto inflectional ending −o. However, the original inflection will occasionally be retained, as if it were part of the root, in order to disambiguate from a more common word. For example, a virus (from Latin vir-us) is virus-o instead of the expected *vir-o in order to avoid confusion with vir-o (a man), and the Latin root corp-us is the source of both korp-o (a living body) and korpus-o (a military corps). Similarly, when the sound ĥ is replaced with k, as it commonly is (see Esperanto phonology), the word ĥoro (a chorus) is replaced with koruso to avoid creating a homonym with koro (a heart). The redundant inflection may have been inspired by Lithuanian, which otherwise contributed relatively little to Esperanto: compare fokuso (focus), kokoso (coconut), lotuso (lotus), patoso (pathos), radiuso (radius), sinuso (sine), and viruso (virus), with Lithuanian fokusas, kokosas, lotosas, patosas, radiusas, sinusas, and virusas (virus) vs. vyras (man).

Proto-Esperanto had voicing ablaut, traces of which remain in a few pairs of words such as pezi 'to weigh' (to have weight) and pesi 'to weigh' (to measure the weight). Because little of Proto-Esperanto has survived, it is not clear which other aspects of Esperanto etymology might date to this period.[15]

• Vilborg, Ebbe, Etimologia Vortaro de Esperanto. Five volumes, Stokholmo, 1987–2001.
• Cherpillod, André, Konciza Etimologia Vortaro. One volume, Roterdamo, 2003.

• Andras Rajki. "Etymological Dictionary of the Esperanto Language". Archived from the original on 2007-10-12.
  Note: This dictionary should be used with caution. For example, amelo (starch) is given as a rare example of a Greek word that does not occur in Latin. However, it is not only a Latin derivation (from amyl-um), but more directly derives from German amel-.
• Esperanto page with a list of languages sorted by similarity of basic vocabulary. EVOLAEMP Project, University of Tübingen.