SUMMARY OF INTERLINGUA GRAMMATICAL FORMS

Largely summarized from:
Alexander Gode and Hugh E. Blair
Interlingua: a grammar of the international language
New York: Frederick Ungar Publishing Co., 1955 (2nd edition)
ISBN 0-8044-0186-1
(with some supplemental material)

(This summary is not a complete statement
of Interlingua grammar and usage.)

0. SPELLING AND PRONUNCIATION.
1. ARTICLES.
2. NOUNS.
3. ADJECTIVES.
4. ADVERBS.
5. PRONOUNS.
6. VERBS.
7. CALENDAR.
8. NUMBERS.
9. GRAMMATICAL WORDS.
10. WORD BUILDING.

Spelling and Pronunciation

Interlingua is written with the conventional twenty-six letters of the Latin alphabet without diacritical or accent marks. Proper names and unassimiliated foreign words may have letters with diacritical or accent marks and retain their foreign pronunciation.

In general, pronunciation is "continental," similar to that in western Europe. However, sounds are somewhat fluid within types and may be influenced in part by neighboring sounds and by the native habits of speakers. The emphasis in speech is for comprehension, not meticulous exactness of enunciation. Vowel sounds (and letters) are generally pure and coincide mostly with Romance pronunciation (although written u is not pronounced as the sound represented by the single letter in French lune.) English speakers, in particular, must take care not to obscure the pronunciation of unstressed vowels.

The following letters agree with the normal English pronunciation: b, d, f, k, l, m, n, p, ph, qu, v, w, z.

c before e, i, y is pronounced like ts; otherwise (as also ch) like k.
g like g in good (like z in azure in the suffix -age).
h as in English (or optionally silent for some speakers), except silent after r and t.
j like z in azure. (Some speakers pronounce as g in gem or y in yes.)
r will vary somewhat according to the native habits of speakers, but speakers of some dialects of English must take care not to elide it after vowels.
s generally unvoiced, but voiced or unvoiced between vowels (ss unvoiced between vowels).
t as in English; ti before vowels varies somewhat among speakers but often as tsy unless stressed or preceded by s.
x generally as in English.
y unstressed before vowels as y in yes; otherwise as i.

Vowels in diphthongs retain their independent sound values, except that unstressed i and u become semiconsonants before following vowels. Stressed e and i are separated by a syllable break from a following a, e, o. Double consonants merge in pronunciation.

A main stress accent falls normally on the vowel before the last consonant (except that the plural ending does not change the stress from the singular form). Adjectives and nouns ending in -le, -ne, and -re preceded by a vowel have the stress on the antepenultimate syllable. The stress falls on the syllable preceding the suffix in words formed with the suffixes -ic, -ica, -ico, -ida, -ide, -ido, -ima, -ime, -imo, -ula, -ule, -ulo, -uple, and -ulo. Variations from stress rules are marked in dictionaries. (See also the section on verbs, below.)

Stress regularity should not be exaggerated. Understandability is the principal concern. Stress is not random, but the Interlingua word is the same whether it is pronounced, for example, kilOmetro or kilomEtro, according to speakers' native habits.

Within a sentence, proper names are capitalized but not derivatives from them. Punctuation marks and their values are generally those of English but need not obey absolute rules as long as they follow the rhythms of the spoken sentence and the sense is clear.

Collateral Orthography

There is an allowed collateral orthography, which is employed by some users (although only occasionally used):

1. Double letters representing a single consonant sound are replaced by the single consonant letter, except for ss, which is kept doubled to preserve the sound. (cc before e, i, y does not represent a single consonant sound.)
2. Vowel y > i
3. ph > f
4. ch representing the sound of k is retained only before e and i; elsewhere it is replaced by c.
5. For silent h, rh > r and th > t.
6. J replaces g and gi to represent the sound of z in azure.
7. Suffix -age (and terminal sound group -age when it is not a suffix) is replaced by -aje. Suffix -isar is replaced by -izar (and z appears in its derivatives).
8. Final e is dropped after t preceded by a vowel except in words which have the stress on the antepenultimate syllable. Likewise for final e after n, l, and r when these are shortened collateral spellings under item 1. above. (Present tense and imperative verb forms are not affected by this rule.)

Articles

Le is the definite article, the, and is invariable. It does not change (when used as an article; see below) for number or gender and is generally used as in English, with some variations, such as that it is not omitted with abstract nouns representing the entire class, species, etc. It need not be omitted with titles preceding proper names (except in direct address).

Un is the indirect article, a(n), and also is invariable. It is identical with the numeral un, 'one'. (When used as a numeral, un sometimes appears in the plural form unes in certain vocabulary expressions such as le unes le alteres, 'one another, each other, etc.'.)

A preceding preposition a or de fuses with an immediately following definite article into the forms al or del. Both articles have the possibility of pronominal use, and in such instances can be pluralized as les and unes (the latter often being rendered as 'some'). In pronominal use, the articles can make a distinction between male and female (not grammatical gender) as le/la and uno/una, all of which have plural forms. The definite article has a neuter pronominal form lo which occurs especially in the expression lo que, 'that which, what'. (It has a rarely used plural los in this construction.)

Nouns

Nouns are recognized by the function they perform in a sentence rather than by a specific set of endings. There is no grammatical gender, although some nouns can indicate a difference of natural sex. (If a noun ending in o specifically indicates a male being, the ending a can indicate the female, and vice versa.) There are no distinct case forms.

The plural is formed by the addition of s after a vowel and es after a consonant. (Final c changes to ch before the plural marker es in order to preserve the pronunciation.) Unassimilated foreign words may retain their foreign plurals. Formation of the plural does not affect accentuation.

Nouns function generally as in English. Note, however, that the widespread English trait of nouns being used extensively as adjectives or attributives before other nouns does not occur in Interlingua. (Nevertheless, proper nouns used as adjectives remain unmodified and are preceded by the nouns they qualify, e.g., 'Roentgen rays', radios Röntgen; 'Geiger counter(s), contator(es) Geiger).

Adjectives

Although adjectives most commonly end in e, c, l, n, or r, these final letters are not conclusively indicative that a word is an adjective, which can only be determined by the function it performs in a sentence or, at times, by a suffix which happens to occur with no other part of speech.

Adjectives do not have inflection, nor do they agree with the nouns they modify. Adjectives may either precede or follow a noun. The latter position is more frequent. "Adjectives preceding a noun tend to suggest that what they express is an essential feature of the noun concept and not merely a feature distinguishing the present representative of the noun concept from others." [p. 13, §33] However, brief adjectives such as bon, parve, alte, etc., may precede their nouns as a matter of rhythm or personal preference.

The adverbs plus (for the comparative) and minus, together with the article le (for the superlative) form degrees of comparison. (See below for a few irregular alternative comparisons.) A so-called absolute superlative (very, most, etc.) is expressible with the suffix -issime.

When the sense allows, adjectives can be used as nouns or pronouns, in which case they can be pluralized and/or take the article.

Alternative Comparisons

Adverbs

Adverbs may be either primary or derived; there are also adverbial phrases. Primary adverbs are dictionary items and require no grammatical remarks. Adverbs derived from adjectives are formed with the suffix -mente (-amente after a final c) appended to the full form of the adjectives. The functions of adverbs are largely those of English adverbs.

A few adverbs which seem to be derived irregularly from adjectives (such as bon/ben) can be treated as primary adverbs, in that they do not serve for additional adverbial derivations. However, regular derivation (such as bonmente = ben) is still possible.

Regular comparison of adverbs is the same as that of adjectives. Adjectives in -issime can form corresponding adverbs in -issimo.

Adverbs (except those indicating a certain determined time) usually precede the words they modify. (Longer adverbs may follow, for emphasis or style.) When an adverb or adverbial phrase modifies a clause or sentence as a whole, it appears in initial or final position or is set off by commas. When an adverb (especially non) and a non-subject pronoun both precede a verb, the pronoun is closer to the verb. The adverb non precedes the verb it modifies.

An and esque are interrogative particles which have no immediate counterparts in English and which convert a simple declarative sentence into a question. They should not both be used in a single text.

Pronouns

Personal pronoun table:

                   OBJ              POSS    POSS
         SUBJ      PREP  OBJ  REFL  ADJ     PRON

1p sg    io        ......me.....    mi      mie
2p sg    tu        ......te.....    tu      tue
3p sg m  ille..........  le   se    su      sue
3p sg f  illa..........  la   se    su      sue
3p sg n  illo, il......  lo   se    su      sue

1p pl    nos....................    nostre......
2p pl    vos....................    vostre......
3p pl m  illes.........  les  se    lor     lore
3p pl f  illas.........  las  se    lor     lore
3p pl n  illos.........  los  se    lor     lore

         on        uno..........................

[NOTE: usage of the second person singular pronoun tu and its forms varies. Some users employ it merely as a singular form without connotation of familiarity, and some users employ it particularly as a familiar form, extending vos and its forms to both singular and plural.]

cuje : "whose"
qui : "who, whom" only for persons and only as a subject or after prepositions
que : (primarily) relative pronoun
qual : relative adjective (can be pronominalized with le and then pluralized: le qual and le quales)
(Relative pronouns are not elided in Interlingua as they sometimes are in English.)
il : an unstressed third person singular neuter form for use as a grammatical subject (sometimes elided)
ella : a collateral (now rarely used) form for illa
In the plural, illes does not necessarily indicate a plurality of masculine beings.
Possessive pronouns are often used with le : Illo es le mie. = It is mine.

Reflexive constructions are primarily of the type in which the object of the verb happens to be logically identical with the subject. ... Reflexive constructions are also used to express passive ideas when there is no agent involved.
...
Second-case personal and reflexive pronouns (except in prepositional constructions) precede the simple tense forms of the verb but follow the participles, imperative forms, and the infinitive.
[Interlingua Grammar p. 25, §§67-69]

"In a combination of two pronouns, one personal and the other reflexive, the latter precedes."

Demonstratives are adjectives which can be used as pronouns. Iste, this, is the demonstrative of proximity. Ille, that, is the demonstrative of remoteness.

Verbs

Conjugation

In the future tense, the a ending receives the word stress; in the conditional, the e of the ending receives the stress. Some users employ the auxiliary verb va plus the infinitive to express the future, as in English.

Passives are formed from the corresponding tenses of esser plus past participle. Reflexive constructions can be used to express passive ideas when there is no agent involved.

There is no verbal auxiliary corresponding to English to do in interrogative, negative, and emphatic constructions, and there are no crystallized progressive forms.

The infinitive can be used to express general orders, prohibitions, etc.

The following alternative forms are available:

es = esse (singular/plural)
son = esse (plural)
era = esseva
sia = esse (optional irregular subjunctive or imperative)
ha = habe
va = vade

Apart from (the only occasionally used irregular) sia, there is no distinct subjunctive. Subjunctive or third-person imperative is often expressed by the indicative following que.

The infinitive [Inf.] serves as a verbal noun in place of the English gerund.

Prepositions before Infinitives

If an infinitive can be construed as a noun or taking the place of a noun, no preposition need be used. For example, in the expression "It is difficult to walk in the sand," the infinitive is equivalent to the logical subject and hence the equivalent of a noun: "To walk in the sand is difficult," so there is no preceding preposition: [Il] es difficile vader in le arena or Vader in le arena es difficile. If a transitive verb is followed by a dependent infinitive, as in "I plan to go to the countryside" (Io plana vader al campania), the idea can also be expressed more or less smoothly by a noun ("I plan a trip to the countryside"), so again, no preposition is used. Thus, a preposition does not introduce a dependent infinitive after a transitive verb.
(Interlingua Grammar §87, p. 31)

[NOTE: Because the source languages for Interlingua are not entirely consistent among themselves on the use of prepositions before infinitives, use or non-use of the prepositions de and a before infinitives varies somewhat in practice among speakers and writers, as long as the intended sense is clear.]

Double-Stem Verbs

Forms derived from certain verbs come from a second or double stem, often based on the Latin supine stem.

In Interlingua the irregular second stem of verbs has nothing to do with matters of conjugation. It is a stem which occurs in certain derived nouns and adjectives and prevents these from assuming unnaturally distorted forms .... Furthermore, the "regular" type ... need not be considered "wrong" but may be used whenever it seems stylistically possible or preferable.
    In active word bulding it will be found that the irregular second stem occasions few difficulties but often simplifies the process of derivation.
[Interlingua Grammar page 85, Appendix 1]

Calendar

[NOTE: For avoidance of any contemporary religious connotations for name days, one occasionally encounters the non-standard, unofficial forms soldi and saturdi for Sunday and Saturday, respectively.]

Numbers

For other numbers, <ordinal> = <cardinal> + -esime
adverbial numerals: ordinal -e > -o or use -mente

half = medie/medietate
dozen = dozena
Other collective numerals are formed on the pattern of the suffix -ena(s) attached to the simple cardinal numbers.

Comma for decimal point.
-illion/-illiardo de <cosas>

Grammatical Words

Word Building

Nouns derived from Nouns

Adjectives derived from Nouns

Verbs derived from Nouns and Adjectives

Nouns derived from Adjectives

Adjectives derived from Adjectives

Derivations from Verbs

General Prefixes

Technical Prefixes (modifying nouns and adjectives)

(NOTE: the Interlingua Grammar, pp.78ff [§161], lists a number of affixes, many derived from Greek (a few from Latin), which may also be used in word building and which are similar to their use in English and many of the west European languages, especially in technical and scientific compounds.)