The language Interlingue ([interˈliŋɡwe]; ISO 639 ie, ile), originally Occidental ([oktsidenˈtaːl]), is an international auxiliary language created in 1922 by Edgar de Wahl, who sought to achieve maximal grammatical regularity and natural character. The vocabulary is based on pre-existing words from various languages and a derivational system which uses recognized prefixes and suffixes.

Alphabet and pronunciation Interlingue is written with 26 Latin letters: a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z. The letters of the alphabet are pronounced as a, be, ce, de, e, ef, ge, ha, i, jot, ka, el, em, en, o, pe, qu, er, es, te, u, ve, duplic ve, ix, ypsilon, and zet.Grammatica de Interlingue in English , F. Haas 1956. Read 31 October 2013. Accents are written on the five vowels to indicate irregular stress, with the acute accent (á é í ó ú) preferred, but others (è, ê, etc.) permitted.

Grammatical endings Grammatical endings are used, though to a far lesser extent than more schematic planned languages such as Esperanto and Ido in which parts of speech are marked with obligatory endings. Only a few parts of speech (such as verbs in the infinitive) in Interlingue have entirely obligatory endings, while many others either have endings the usage of which is optional and sometimes recommended. Some grammatical endings are:

ar, er, ir: verb infinitive. far (to do), posser (be able), scrir (to write) e: the general substantival (noun) ending used obligatorily to differentiate nouns from other parts or speech, for reasons of pronunciation, or optionally for euphony. Examples of obligatory -e endings: capitale (capital, noun) vs. capital (capital, adjective), contenete (content) vs, contenet (contained), sud (south, adjective) vs. sude (south as an independent noun, as in the north and the south). A final -e is recommended in words ending with -s to avoid confusion with the plural (curse, sense), -ir, -er- and -ar endings to avoid confusion with the verb infinitive (dangere, desire, papere), and other such areas where its addition aids in differentiation or pronunciation. Optional -e endings: can or cane (dog), Pentecost or Pentecoste (Pentecost). The -e and other endings are often omitted for poetic or euphonic reasons.Poem in Cosmoglotta 289 (summer 2000) with unwritten endings in parentheses: Quo es li vive? On mori lent, li fin silent...Un promenad(a) in verdi parc(o). Nu flores resta sur li sarc(o)...Quo es li vive? Un rubi ros(e), mysterios(i), quel lentmen perdi su color(e). Quo resta? Solmen li dolor(e)...Quo es li vive? Tristess(e)? Chagrin(e)? Li mort(e) – - e fin(e)? Partú triumfa li amor(e), quam ombre fugi li dolor(e)! Quo es li vive? Tam bell, tam brev(i)... Un dulci rev(e) – Un gay canzon quam sol(e) aurin. Yo va amar it til li fin(e)!! i: the general adjectival ending, similar to -e in usage. Examples of obligatory -i endings: pigri (lazy) and acri (sharp) to enable pronunciation, verdi (green, adjective) to distinguish from verde (green, noun). Examples of optional -i endings: etern vs. eterni (eternal), imens vs. imensi (immense). a: nouns that end in e formed from an -ar verb are often written with the -a ending if one wishes to emphasize the verbal (active) aspect. A me veni un pensa (a thought occurs to me) vs. Penses e paroles (thoughts and words). The a ending also makes nouns feminine: anglese (English person), angleso (Englishman), anglesa (English woman). This does not apply to nouns that on their own indicate the gender (patre, matre). o: indicates the masculine gender in the same way a indicates the feminine.

Articles Like English, Interlingue has definite and indefinite articles. The definite article (the) is li, and the indefinite (a, an) is un.

The ending of the definite article can be modified to lo (masculine), la (feminine), lu (neuter), lis (plural), los (masculine plural), e las (feminine plural). Of these, the forms lu and lis are most common: lu in the same sense as Spanish lo and English that which, as in Ne li aprension de un lingue es lu essential, ma su usation (that which is essential is not the learning of a language, but using it), and lis to pluralize words that are difficult to pluralize on their own: lis s (the s's).

Nouns Interlingue does not have grammatical gender. The plural of a noun is formed by adding -s after a vowel, or -es after most consonants.The Basis of International language . Read 1 November 2013. To avoid pronunciation and stress changes, words ending in -c, -g, and -m only add an -s: un libre, du libres, un angul, tri angules, li tric, li trics, li plug, li plugs, li album, pluri albums, li tram, du trams.

Adjectives

Pronouns Personal pronouns Interlingue has two forms for the personal pronouns: one for the subject form (nominative), and one for the object form (accusative or dative, i.e. the oblique form): +SubjectObjectPossessiveSingularPluralSingularPluralSingularPlural1styonoime nosminor2ndtuvutevostuivor3dmasculineililloslelossulorfeminineellaellaslalasneutralitiliitles The formal second person is vu, which is also the second person plural. The indefinite personal pronoun "one" is on. If necessary, one can specify the gender of third person plural by using illos (masculine) or ellas (feminine).

In the object form the pronouns are: me, te, le, la, it, nos, vos, and les (with los and las as specific masculine and feminine forms, respectively). In the oblique case, the pronouns are me, te, il (or le), noi (or nos), voi (or vos), and ili (or les), varying by user and situation for pronouns except me and te. The possessive pronouns are mi, tui, su (his/her/its), nor, vor and lor. They may be pluralized: li mi (mine, singular), li mis (mine, plural), li nor (ours, singular), li nores (ours, plural).

Verbs Verbs in Interlingue have three endings: -ar, -er, and -ir. Conjugation is performed with a combination of endings and auxiliary verbs. The verb esser (to be) is exceptional in being written es in the present tense, though the esse form is seen in the imperative. +Simple Verb TensesFormInterlingueEnglishNotesInfinitivear / er / iramar / decider / scrirto love / to decide / to writePresenta / e / iyo ama / decide / scriI love / decide / writePast -tyo amat / decided / scritI loved / decided / wrotestress thus falls on the last syllable: yo amatFutureva + inf.yo va amar / decider / scrirI will (shall) love / decide / writeva on its own is not a verb (to go = ear or vader)Conditionalvell + inf.yo vell amar / decider / scrirI would love / decide / writeAlso used for hearsay: Un acusation secun quel il vell har esset... - An accusation alleging him to have been... (lit. an accusation according to which he would have been...)Imperativea! / e! / i!ama! / decide! / scri!love! / decide! / write!Imperative of esser is esse. +Compound Verb TensesFormInterlingueEnglishNotesPerfectha + tyo ha amat / decidet / scritI have loved / decided / writtenha on its own is not a verb (to have = haver)Pluperfecthat + tyo hat amat / decidet / scritI had loved / decided / writtenFuture Perfectva har + tyo va har amat / decidet / scritI will (shall) have loved / decided / writtenPerfect Conditionalvell har + tyo vell har amat / decidet / scritI would have loved / decided / writtenFuture in the pastvat + inf.yo vat amar / decider / scrirI was going to love / to decide / to writePrecativeples + inf.ples amar! / decider! / scrir!please love! / please / write!Hortativelass + inf.lass nos amar! / decider! / scrir!let's love! / decide! / write!Optativemey + inf.yo mey amar / decider / scrirMay I love / decide / writeOnly the same as English may in the optative mood (as in "May his days be long" or "May the Force be with you", not "I may or may not go").Present participle -ntamant / decident / scrientloving / deciding / writing -ir verbs become -ientGerund (adverbial participle) -nteamante / decidente / scriente(while) loving / deciding / writing -ir verbs become -iente The present participle is used to qualify nouns: un cat ama, un amant cat (a cat loves, a loving cat) and is often seen in adjectives such as fatigant (tiring, from fatigar, to tire). The gerund is used to indicate another action or state of being going on at the same time: scriente un missage, yo videt que... (writing a message, I saw that...).

Many further combinations of endings and auxiliary verbs are possible. Some examples:

Ili vell har esset constructet = They would have been constructed

Hante audit to e sin mem regardar li dors del du altres... = Having heard that and without even looking at the backs of the others... (ha + gerund)

Other notes on verbs:

The subjunctive does not exist in Interlingue: yo vole que tu ama (I want you to love). Mey is often used to express it when necessary, however, frequently after que: Yo vole que tu mey amar (I want you to love, lit. I want that you may love).

Hay is a standalone verb signifying there is or there are: Hay du homes in li dom (there are two people in the house). As a standalone verb there is no official infinitive but users of the language often conjugate it as if there were (hayat, etc.). Other ways of expressing there is or there are: esser (esset nequó altri a far = there was nothing else to do), exister (it existe du metodes = there are two ways), trovar se (in li cité trova se tri cavalles = there are three horses in the city), etc.

The passive is formed using the verb esser: yo es amat (I am loved). Se makes the verb refer to itself (reflexive form) which often functions as a shorter way to form the passive: li frontieras esset cludet = li frontieras cludet se (the borders were closed).

The progressive tense (-nt) is not used with the same frequency as in English (what are you doing? = quo tu fa?, not quo tu es fant?). It emphasizes the continuity of the verb and is often used in storytelling (noi esset marchant vers li rivere quande... = we were walking towards the river when...)

The verb star (to stand) may be used to emphasize the completion of a verb: li dom sta constructet (the house stands constructed, i.e. it is completely built).

The verb ear (to go) may be used to emphasize the continuity of a verb: li dom ea constructet (the house is being built).

The double negative is permitted, and was even recommended by de Wahl for its internationality and precision. De Wahl gave the following phrase as an example: "Yo ha trovat li libre, quem vu ha dat me, in null loc, quem vu ha indicat me" (lit. I found the book you gave me nowhere you indicated me, thus "I didn't find the book anywhere you told me to look"). In this phrase, not permitting a double negative would result in ambiguity up to the word null (the only indication of a negative in the phrase), recommending Yo ne ha trovat li libre...in null loc. An obligatory double negative was never imposed and later Occidentalists found that they rarely used it, but it remained permitted and is seen occasionally.

The infinitive may also used as a mild or impersonal imperative: ne fumar – no smoking; bon comprender: un crímine es totvez un crímine – let's be clear (lit. understand well): a crime is still a crime.

Adverbs Interlingue has primary adverbs and derived adverbs. Primary adverbs are not generated from other parts of speech and are thus not formed using any special endings: tre (very), sempre (always), etc.

Derived adverbs are formed by adding the suffix -men to an adjective (rapid = quick, rapidmen = quickly), cognate with French -ment, Italian -mente, and others. The ending -men was inspired by Provençal and spoken French (which does not pronounce the t in -ment) and chosen over -mente to avoid clashing with the noun ending -ment and other nouns in the language derived from the past tense in -t. Adjectives may be used as adverbs when the sense is clear:

Il ha bon laborat = He has worked well ("He has worked good")

Noi serchat long = We looked for a long time ("We searched long")