Occidental/Interlingue is a constructed language first published as “Occidental” in 1922 by Edgar de Wahl. The language was renamed to “Interlingue” in 1949 so speakers in the Eastern Bloc could continue to speak it without arousing suspicion that they were Western spies or something (I doubt this worked).

Occidental was designed to be a naturalistic language based mostly on the Romance languages with some English and other Germanic influence, but was still considerably more regular than the similar Interlingua which came out in 1951. This was thanks largely to its invention and use of de Wahl’s rule, which outlined how to derive nouns, adjectives, etc. from verbs in a mostly-regular way (with six exceptions):

Flow chart illustrating how Occidental forms nouns from verb roots

Image by Mithridates on Wikipedia, licensed under the CC-BY-SA-4.0 licence. Original found here(external link).

Occidental draws on regular word endings, many of which were later also borrowed by Novial:

  • -e is the general ending for nouns. It seems like it can be dropped if it is not needed to make the sentence’s meaning clear.
    • -o can be used instead to form an explicitly masculine noun.
    • -a can be used to make an explicitly feminine noun.
  • -i is the general ending for adjectives, and can be dropped in similar situations as the -e for nouns.
  • Verbs can end in -ar, -er or -ir.
  • Derived adverbs are made by adding -men (cf. French -ment) to another word. You can just use the adjective if the meaning is clear though. Primary adverbs, which are not derived from other words but are basically their own roots, have no particular ending.

Verb conjugation in Occidental is very regular, and uses a combination of word endings (for the past tense) and auxiliary verbs (for the future and conditional).

Tense Ending Examples
Infinitive -ar / -er / -ir amar, decider, scrir
Present -a / -e / -i* ama, decide, scri
Past -t amat
Future va + inf. va amar, va decider, va scrir
Conditional vell + inf. vell amar, vell decider, vell scrir
Imperative -a, -e, -i* ama, decide, scri

* = The present-tense form of esser “to be” is irregular es. However, the imperative form is the regular esse.

The perfective aspect can be added with auxiliary verb har (e.g. ha amat “have loved”, hat amat “had loved”, va hat amat “will have loved”, vell hat amat “would have loved”). There is also a future in the past, e.g. vat amar “was going to love”. There are three more auxiliary verbs that are considered to form compound tenses:

  • Precative (ples + inf.): Ples amar “Please love!”
  • Hortative (lass + inf.): Lass nos amar “Let us love!”
  • Optative (mey + inf.): Yo mey amar “May I love” (think like in “May the force be with you”)

Finally, you can form the present participle by adding -nt (-ent for -ir verbs) and the gerund with -nte (-ente for -ir verbs) to the present-tense form of the verb.

There are a number of affixes, mostly based on Romance language affixes, that can be added to words to expand their meaning.

The table of correlatives is based on the Romance languages and as such has some overlap with Ido:

qu- (inter.) t- (demon.) alqu- (undef.) nequ- (neg.) -cunc (indef.) Ø (collec.)
-i (people)1 qui (who) ti (that person) alqui (someone) nequi (no one) quicunc (whoever) omni (everyone)
-o (things) quo (what) to (that) alquo (something) nequo (nothing) quocunc (whatever) omno (everything)
-el (both) quel (which) tel (such) alquel (any)2 nequel2 quelcunc (whatever) chascun (each)
-al (quality)3 qual (which, what a) tal (that) alqual (any kind) noqual qualcunc
-am (way, mode) quam (as) tam (so) alquam (somehow) nequam quamcunc (however)
-ant (quantity) quant (how many) tant (so much) alquant (somewhat) nequant quantcunc (whenever)
-ande (time) quande (when) tande (then) alquande (some time) nequande (never) quandecunc (whenever) sempre (always)
-u (place) u (where) ci (here) / ta (there)4 alcu (somewhere) necu (nowhere) ucunc (wherever) partú (everywhere)

Correlatives can also take the plural ending -s/-es.

What I have read online is that Occidental is easier to actively learn than Interlingua, due to its higher level of regularity. However, the same people also seem to say that it can be harder to understand when spoken, mostly when the speaker’s native language is Germanic. To me it sounds like the issue is that Occidental sounds close enough to a Romance language that people’s brains parse it as that, then hit confusion at the Germanic-origin words (especially if the speaker doesn’t just pronounce it exactly as if it was a Romance word, i.e. Germanic speakers transferring their knowledge of their own languages to this one).

Don Harlow, who you might remember for his inaccurate criticisms of Ido, criticised Occidental on the basis that he thinks de Wahl and his original adherents in the 1920s and 30s were racist. His argument for that is that they were only interested in attracting Europeans and “Europeanised” Asians to their movement (according to him). He linked to some citation which was a broken link so idk. At any rate, I don’t believe this criticism applies to 21st century Occidental enthusiasts.

  1. This series also has optional accusative forms ending in -em, like quem “whom”. ↩︎

  2. Alcun “some” and necun “no” are the adjectival forms of alquel and nequel↩︎

  3. The -al series requires -men added to the end to make them “adverbs”, so qualmen “how” (not sure how this is an adverb though) and talmen “that way”. ↩︎

  4. These particles can also be added to the demonstrative ti, for ti-ci “this thing” and ti-ta “that thing” (cf. French and how it has ce, ceci and cela which I probably spelt wrong but w/e) ↩︎