Irregularities and exceptions in Interlingua

From Wikipedia, the free encyclopedia
Jump to: navigation, search

The term irregularities or exceptions in Interlingua refers to deviations from the logical rules in a few grammatical constructions in the international auxiliary language Interlingua. These oddities are a part of the standard grammar. These special cases have crept into the language as a result of the effort to keep it naturalistic. Most of these irregularities also exist in Interlingua's source languages; English, French, Italian, Spanish, Portuguese, and to a lesser extent German and Russian. This feature of the language makes Interlingua more familiar to the speakers of source languages. And at the same time, it makes the language more difficult for others.

The speakers of the source languages don't perceive all deviations as irregular. For instance, Interlingua has three different words for English am (so), is (es) and are (son). While most English speakers will not find any thing abnormal about it, speakers of a few other languages may find the use of three words to express the concept of 'simple present' as unnecessary.

Interlingua is notable in the sense that unlike most auxiliary languages, that seek to minimise or eliminate any irregular aspects, Interlingua takes a flexible approach. It is mandatory to use certain exceptions in Interlingua while others have been kept optional.

Mandatory exceptions[edit]


Interlingua doesn't have a 'one letter one sound' orthography. As in English, several letters can be pronounced in different ways; depending on where they are in a word. For instance, the letter S can be pronounced as either [s] (stato) or [z] (Chinese). Here is a list of other mandatory exceptions in pronunciation:

Letter / Digraph Possible Pronunciations[1] Rules Examples
c [k]
[ts] (or [s])
[k] when c is followed by a, o, u or any consonant
[ts] (or /s/) when e, i or y come after c
camera, crear
acido, Cinderella
ch [k]
like [k] in words of Greek origin
[tʃ] only in a few words (very rare)
[ʃ] in several words that come from the French
cholera, chrome, echo
machine, chef
h [h]
usually [h]
but silent after r and t
rh [r] always pronounced like [r] rhetorica, rheumatic
s [s]
[s] if followed by a consonant
[z] between vowels
son, spa
accusative, abstruse
sh [ʃ] always pronounced like [ʃ] Shakespeare.
th [t] always pronounced like [t] theatro
ph [f] always pronounced like [f] photographia, photosynthese
t [t]
[t] when it is followed by a, o, u or any consonant
[ts] when e, i or y come after t
u [u:]
[u:] when between two consonants or stressed before a vowel
[w] when unstressed and precedes a vowel
luna, plural
persuade, superflue
x [ks]
usually [ks]
like [z] when precedes a vowel
between two vowels
xenon, xenophobia
y [j]
[j] when unstressed before vowels
other like [i:]
Yugoslavia, yoga
tyranno, typo

Besides, there are also unassimilated guest words that retain their original pronunciation and spelling; though the diacritics are usually removed. Commons examples of such words are radios Röntgen (X rays) and kümmel.


Just like in English, where I am is usually contracted to I'm and he is to he's, such contractions are also found in Interlingua and these two are compulsory to observe:

Words Contraction Example
de (of) + le (the) del del matre (of the mother)
a (to) + le (the) al al luna (to the moon)


Plurals can be formed in three different ways depending on the ending of a noun.

Ending Add Example
ends in a consonant other than c -es conversation - conversationes
pais - paises
ends in c -hes roc - roches
choc - choches
ends in a vowel -s radio - radios
academia - academias

There are also irregular plurals that occur in guest words. The common ones are tests (from 'test'), addenda (from 'addendum') and lieder (from 'lied').


Numbers Logical Name Name used
10 unanta dece
20 duoanta vinti
30 tresanta trenta
40 quatranta quaranta
13 tresdece tredece
14 quatrodece quattuordece
15 cinquedece quindece
16 sexdece sedece

Parts of speech[edit]

  • Not all adverbs are derived from adjectives.
  • If an adjective ends with -c, an adverb derived from it takes -amente (instead of -mente).
  • Sia is the imperative form of esser ('to be'): Sia contente! 'Be content!'



  • if s is between vowels, it can be pronounced [z], like in "these" (instead of the [s] of "stay")
  • if x is between vowels, it can be spoken like the [ɡz] in "exact" (instead of like the [ks] in "fox")


Optional short forms[edit]

  • "ha" for "habe", 'has', 'have'
  • "va" for "vade", 'goes', 'go'
  • "es" for "esse", 'is', 'am', 'are'

Alternative forms of esser[edit]

Note. These forms are rarely used.
  • "so", a first-person singular present tense
  • "son", a plural present tense
  • "era" for "esseva"
  • "sera" for "essera"
  • "serea" for "esserea"

Comparative and superlative adjectives[edit]

  • "(le) minor" instead of "(le) plus parve"
  • "(le) major" instead of "(le) plus magne"
  • "(le) melior" instead of "(le) plus bon"
  • "(le) pejor" instead of "(le) plus mal"
  • "minime" instead of "le plus parve" or "le minor"
  • "maxime" instead of "le plus magne" or "le major"
  • "optime" instead of "le plus bon" or "le melior"
  • "pessime" instead of "le plus mal" or "le pejor"


  1. ^ Alexander Gode & Hugh Blair (2011-10-23). "Grammar of Interlingua (Second Edition)". 

External links[edit]