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Morphology of Spanish Verbs and Nouns



Before looking at verbs and nouns in detail, it is as well to be clear about where the stress falls on a Spanish word and when a written accent is required. This is because changes to the form of a noun or verb often require an accent to be added or removed. The stress falls:

Exceptions to either rule are marked with a written accent: comí I ate, avión aeroplane, árbol tree.

A written accent is also used on such pairs of vowels as , , to show that the í or ú constitutes a separate syllable. So caigo I fall has two syllables, with the stress on cai, but caído fallen has three syllables; similarly au in aula classroom constitutes one syllable, but in baúl is two syllables. This use of the accent creates words that carry a written accent even though they do not contravene the rules for stress.



The seemingly large number of tenses in Spanish becomes more manageable if you think of them in groups. The basic group consists of the five 'simple' tenses: present hablo I speak; future hablaré I shall speak; conditional hablaría I would speak; past hablé I spoke; imperfect hablaba I was speaking. Alongside these is a second group of five 'perfective' tenses, and a third group of five 'progressive' tenses, as follows:

   Simple          Perfective             Progressive
   ------          ----------             -----------
   hablo           he hablado             estoy hablando
   I speak         I have spoken          I am speaking
   hablaré         habré hablado          estaré hablando
   I shall speak   I shall have spoken    I shall be speaking
   hablaría        habría hablado         estaría hablando
   I would speak   I would have spoken    I would be speaking
   hablé           hube hablado           estuve hablando
   I spoke         I had spoken           I was speaking
   hablaba         había hablado          estaba hablando
   I spoke         I had spoken           I was speaking

Simple, perfective and progressive are 'aspects'. English has the same three aspects, used in the same way as in Spanish: simple como I eat, perfective he comido I have eaten, progressive estoy comiendo I am eating. Both Spanish and English also have a combined perfective-progressive aspect, he estado comiendo I have been eating, which the Language Engine doesn't include.

The perfective tenses are formed with the corresponding simple tense of haber to have followed by the past participle - so the perfective conditional consists of the conditional of haber and the past participle, the perfective past consists of the past of haber and the past participle, and so on. Similarly, the progressive tenses are formed from the equivalent part of estar to be and the present participle. The Language Engine achieves this by replacing the main verb (the 'Headword') with haber or estar and changing the aspect to 'simple', constructing the appropriate form, then restoring the main verb to make the past or present participle.

It will be seen that there are two perfective tenses referring to prior time - the perfective past and the perfective imperfect. The perfective imperfect is the one in everyday use. The perfective past is used only in particular constructions in literary Spanish.


The tenses shown above are those of the 'indicative mood': the two other moods are the 'subjunctive' and the 'imperative', and each of them has a set of tenses. But life is not as grim as this would suggest, because the subjunctive has only two tenses as against five in the indicative, and the imperative has only one tense and no perfective aspect:

   Simple           Perfective             Progressive
   ------           ----------             -----------
Subjunctive Present
   hable            haya hablado           esté hablando
   I should speak   I should have spoken   I should be speaking
Subjunctive Past
   hablara          hubiera hablado        estuviera hablando
   I should speak   I should have spoken   I should be speaking
Imperative Present
   habla!           -                      está hablando!
   Speak!                                  Be speaking!

To be strictly accurate one should also mention the subjunctive future, but it is so rare that it can safely be ignored. And there are two ways of forming the subjunctive past: hablara, estuviera, hubiera as above, and the alternative hablase, estuviese, hubiese. The two forms are exactly equivalent.

The indicative mood is used to make statements, the subjunctive to express 'might-have-beens' or events existing only in the mind of the speaker, and the imperative to give instructions. English has the same three moods: 'The sun's shining' (indicative), 'I wish the sun were shining' ('were', subjunctive), 'Shine!' (imperative, instruction to the sun).

In the Language Engine, subjunctives are shown with 'would' or 'should' in English. This is a rough-and-ready solution, serving mainly as a reminder that a form other than the indicative is called for. The English translation of a Spanish subjunctive depends very much on the context, there being no single version that will serve in all cases.

Forming the Imperative

Forming the imperative is a messy business, because it interleaves two different underlying forms. The 2nd singular and plural are made from a form based on the indicative, but the 1st plural and the 3rd singular and plural are based on the subjunctive. (There is no 1st singular). caber, which has strikingly different indicative and subjunctive stems, illustrates the point well: cabe quepa quepamos cabed quepan.

The subjunctive-based forms are identical with the subjunctive except when an object pronoun is present, as is the case with reflexive verbs. The pronoun goes before the verb in the subjunctive, but after it in the imperative: quiere que nos durmamos she wants us to go to sleep (subjunctive), but durmámonos! let's go to sleep (imperative). The Language Engine handles this by substituting the subjunctive mood whenever it is forming a non-2nd person imperative, then restoring the imperative mood before adding any object pronouns.

The 3rd-person imperative does not express a wish about a third party; it is used to give an instruction to someone one is talking to and whom one would address as Usted. The English equivalent let him do x does not reflect this usage, but was chosen because it illustrates the 3rd-person form.

Names of the Tenses

A problem for learners of Spanish is that different writers use different names for the same tense. This is confusing if - as is likely to be the case - you use more than one reference-work. So it may be helpful to bear the following points in mind:

The Language Engine gives each form a three-word name denoting its aspect, mood and tense ('simple indicative past', 'perfective indicative present'). These names are clumsy, but logical and unambiguous.

Here are some other variations of terminology:

Reflexive Verbs

Reflexive verbs are those which have a direct-object pronoun, referring back to the subject. The pronoun is attached to the end of the infinitive, the present participle and the imperative, but placed in front of the verb in all other tenses: lavarse, estoy lavándome, lavémonos! but me he lavado, me lavé etc. Adding the pronoun to the present participle or the imperative means that an accent is required to preserve the stress.

Defective Verbs

A defective verb is one which lacks certain forms - for example the weather-words tronar thunder, helar freeze, etc., which have only 3rd-person forms. The only other defective verb of any importance is soler to habitually do.


Spanish has six persons in each tense, three singular and three plural ('I', 'you', 'he/she/it' and 'we', 'you', 'they' in English). In Spanish the subject pronouns are optional, and the Language Engine doesn't use them.


People one knows well are addressed using the 2nd-person form, either singular or plural, of the verb; people one doesn't know well are addressed with the 3rd-person form of the verb (singular or plural). The 2nd-person forms are sometimes known as the 'tu' form and the 3rd-person forms as the 'Usted' form. If you omit the subject pronoun and are talking to someone you don't know well, then he/she/it does x and you do x are identical in Spanish.

The Language Engine will not ask you to produce the 'Usted' form of a verb under that name. It will however ask you to produce 3rd-person forms, which are the same thing. The English equivalent is given as 'he/she/it' in order to make it clear that they are 3rd-person forms, but they also mean 'you'.


Spanish verbs are normally classified into three conjugations according to the ending of the infinitive. Generally speaking, each conjugation has its own set of endings for each tense. However, there is a class of 30 or so frequently-occuring words which have an irregular past stem and also take a different set of endings in the past. The Language Engine therefore assigns these verbs, for the past tense only, to an 'irregular past' conjugation.

Different Stems

It is useful to think of the Spanish verb as having a different stem for each group of tenses. This simplifies many apparent irregularities. For example, the future and conditional for any given verb are always formed on the same stem. By calling this the future stem, the Language Engine reduces the future and conditional of decir (for example) from 12 irregular forms (6 persons in 2 tenses) to one, the irregular future stem dir.

The Language Engine recognises a present indicative stem, a present subjunctive stem, a future stem, a past stem, and an imperfect stem. The present subjunctive stem simplifies the presentation of verbs like tener and caer. The past stem removes many anomalies - for example, all the subjunctive pasts and all the 'irregular past' verbs have standard endings on this stem. The imperfect stem simplifies the imperfect of ver.

Stem Changes, Spelling Changes and Endings

Spanish verbs look bizarre because they can change in three places at once: the vowel in the stem (Stem Changes), the consonant at the end of the stem (Spelling Changes), and the ending:


In this example, the vowel in the stem varies between e and i, and the consonant at the end of the stem varies between g and gu, and the ending is ir, o, imos, amos or . But although the result looks complicated, the underlying mechanisms are not difficult to understand.

Stem Changes

Some verbs - not all - change the vowel in their stem in certain persons and tenses. Knowing whether a verb is stem- changing or not is like knowing the gender of a noun - you have to learn it with the verb. About 80 of the 400 verbs in the Language Engine are stem-changing. The Language Engine identifies them by the StemChanging flag in its dictionary.

Stem-changing verbs each fall into one of a few patterns:

o - ue: contar cuento 'tell'
e - ie: cerrar cierro 'close'

o - ue - u: dormir duermo durmió 'sleep'
e - ie - i: sentir siento sintió 'feel'
e - i  - i: pedir  pido   pidió  'ask'

Verbs with two different stem-vowels (those following the first two patterns above) belong to Conjugations One and Two. Verbs with three different stem-vowels belong only to Conjugation Three.

For reasons deeply buried in phonetic theory, the Language Engine calls the first stem (the one with o or e) the simple stem, the second stem (with ue or ie or i) the open-vowel stem, and the third stem (with u or i) the closed-vowel stem. In verbs with the pattern e-i-i, the open-vowel stem and the closed-vowel stem are of course the same. The Language Engine distinguishes those where the open-vowel stem is ie (like sentir) from those where the open-vowel stem is i (like pedir) by a ChangeVowel entry in its dictionary.

One stem-changing verb has u in its simple stem (jugar - juego), and one has i (adquirir - adquiero). In oler - huelo and errar - yerro, the initial ue and ie arising from the stem-change are modified to hue and ye respectively. This is purely a spelling convention - all Spanish words that would otherwise begin with ue or ie are spelt like this.

Choosing the Stem

The changed stems are used only in the present (indicative and subjunctive), the past (indicative and subjunctive), and the present participle.

The present indicative stem consists of the open-vowel stem in all persons except the 1st and 2nd plural, where it consists of the simple stem. The present subjunctive stem is similar, except that verbs having a closed-vowel stem use that in the 1st and 2nd plural:

Indicative:  muero mueres muere morimos morís mueren
Subjunctive: muera mueras muera muramos murís mueran

The past stem consists of the simple stem in the indicative, except that verbs having a closed-vowel stem use it in the 3rd singular and 3rd plural. In the subjunctive, verbs with a closed- vowel stem use it in all persons:

Indicative:  morí    moriste  murió   morimos    moristeis murieron
Subjunctive: muriera murieras muriera muriéramos murierais murieran

The present participle uses the simple stem, or the closed- vowel stem in those verbs which have it: contando, cerrando, durmiendo, sintiendo, pidiendo.

Spelling Changes

The stem of coger sometimes ends with g and sometimes with j:

Indicative Present:  cojo coges coge cogemos cogís  cogen
Subjunctive Present: coja cojas coja cojamos cojáis cojan

The reason lies in the pronunciation. The stem is always pronounced /kokh/, rhyming with Scottish 'loch' or German 'doch'. The sound /kh/ is spelt with g before a front vowel (e or i), but with j before a back vowel (a, o or u). So if the vowel of the ending changes from front vowel to back vowel or vice versa - as it does between the indicative and the subjunctive - the preceding letter must also change to keep the pronunciation the same.

Since all the present subjunctives use the 'wrong' vowel (ar verbs have e, and er and ir verbs have a), the subjunctive is especially prone to these changes. But they occur in other tenses too - notably the irregular-past verbs, where hacer, for example, has hizo in the 3rd singular indicative past. Here are all the changes tabulated, with examples:

Sound   Before a Front Vowel    Before a Back Vowel
-----   --------------------    -------------------
/k/     que  qui  ataque        ca   co   cu  atacar
/g/     gue  gui  seguir        ga   go   gu  sigo
/kh/    ge   gi   coger         ja   jo   ju  cojamos
/gw/    güe  güi  averigüe      gua  guo      averiguar
/th/    ce   ci   cocer         za   zo   zu  cozamos



Here for reference are the endings for all conjugations in all moods and tenses:

Indic. Pres. One       o    as    a    amos    áis    an
Indic. Pres. Two       o    es    e    emos    éis    en
Indic. Pres. Three     o    es    e    imos    ís     en
Indic. Fut.  All       é    ás    á    emos    éis    án
Indic. Cond. All       ía   ías   ía   íamos   íais   ían
Indic. Past  One       é    aste  ó    amos    asteis aron
Indic. Past  Two&Three í    iste  ió   imos    isteis ieron
Indic. Past  Irreg     e    iste  o    imos    isteis ieron
Indic. Impf. One       aba  abas  aba  ábamos  abais  an
Indic. Impf. Two&Three ía   ías   ía   íamos   íais   ían
Subj.  Pres. One       e    es    e    emos    éis    en
Subj.  Pres. Two&Three a    as    a    amos    áis    an
Subj.  Past1 One       ara  aras  ara  áramos  areis  aran
Subj.  Past1 Two&Three iera ieras iera iéramos ierais ieran
Subj.  Past2 One       ase  ases  ase  ásemos  aseis  asen
Subj.  Past2 Two&Three iese ieses iese iésemos ieseis iesen

Notice the following:

Final Accent

If a verb-stem ends in i or u, the stress may either stay on the i or u or move to the previous syllable; if it stays on the i or u, an accent is required. So situar, for example, gives sitúo, but evacuar gives evacuo. You cannot predict how a given verb will behave - you have to learn this feature with the verb. The Language Engine flags these verbs with the TakesAccent flag in its dictionary.

Additional Y

Verbs ending in uir, and also oír hear, add y between the stem and the ending if the ending does not begin with i or y: huyo, construyo.

Initial I

Various changes are made when an ending beginning with i is added to a verb:

Imperative Changes

When a reflexive pronoun is added to the end of the imperative, various adjustments must be made:


Nouns in Spanish are much less complicated than verbs. They have only two forms: singular and plural. The overwhelming majority form their plural in one of two ways: those ending a vowel add s, and those ending a consonant add es. The remainder are plural-only words such as las afueras outskirts, words ending in s that don't change in the plural such as abrebotellas bottle-opener, or foreign words that add s after a consonant (yogur - yogurs). Some minor complexities arise with accents, spelling changes, agreement of qualifiers, and gender.


Changes to the written accent arise with words that add es because the stress stays on the same syllable and the es constitutes an extra syllable. Only words ending in n or s are affected.

Words ending in n or s are normally stressed on the penultimate. Those that carry an accent on the last syllable will lose it in the plural, because the stressed syllable has now become the penultimate: avión - aviones. Likewise those that have no accent on the penultimate in the singular will require one in the plural, because the stress is no longer on the penultimate: crimen - crímenes.

Words ending in a consonant other than n or s, by contrast, are normally stressed on the last syllable. Adding es makes the stressed syllable into the penultimate syllable and also turns the word into one which ends in s, so no written accent is required: pared - paredes. If an accent is present on a word of this type in the singular, its purpose must be to show that the stress is not on the last syllable, so the accent will remain in the plural: árbol - árboles. (In baúl - baúles and país - países the accent is needed to separate the diphthong, and so is retained in the plural.)

Spelling Changes

Spelling changes arise with words whose last letter is z, which are spelt ces in the plural to preserve the pronunciation. Similarly the only two words whose last letter is c in the singular, biftec and bistec, change the c to ques in the plural. g would also require a spelling change, but no nouns have this as the last letter.


Where a noun is followed by a qualifier, as with coche comedor or Guardia Civil, the qualifier may or may not change in the plural. If the qualifier is itself a noun, it doesn't change: coches comedor, huevos ranchero. But if the qualifier is an adjective it changes: Guardias Civiles.


The determiner takes its gender from the noun, so you need to know the gender of the noun. In some cases the gender is predictable - all words ending in ión, for example, are feminine. Where the gender is not predictable, the Language Engine uses a GenderFlag in its dictionary. Some nouns change gender when they refer to persons of different sexes - el ciclista, la ciclista, for example - but this is not always true, and it is easier to regard these as two different nouns. The only complication lies in a handful of feminine words, all beginning with a or ha and having the stress on the first syllable, that take the masculine forms of el and un in the singular (el agua, un hambre), but the feminine form in the plural and the feminine form of any other determiner, whether singular or plural.

Nonexistent Forms

It is not always clear in English whether a given noun actually has a plural form: information exists, but does informations? The converse also applies: congratulations exists, but congratulation perhaps not. Similar questions arise in Spanish. Moreover Spanish and English do not march in step: sus señas her address is plural in Spanish with no singular, but singular in English.

Being concerned with form rather than meaning, the Language Engine takes a robustly tolerant line, and marks very few singulars or plurals as nonexistent, whether in Spanish or English. It allows plurals of countries, for example: two Scotlands. The results may sometimes be thought of as going beyond normal usage, but their purpose is always to illustrate the form.

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