Spanish verbs are a complex area of Spanish grammar, with many combinations of tenses, aspects and moods (up to fifty conjugated forms per verb). Although conjugation rules are relatively straightforward, a large number of verbs are irregular. Among these, some fall into more-or-less defined deviant patterns, whereas others are uniquely irregular. This article summarizes the common irregular patterns.
As in all Romance languages, many irregularities in Spanish verbs can be retraced to Latin grammar.
Due to the rules of Spanish orthography, some predictable changes are needed to keep the same consonant sound before a or o and e or i, but these are not usually considered irregularities. The following examples use the first person plural of the present subjunctive:
Other predictable changes involve stress marks, iâÂÂy alternations and i-dropping, some of which are sometimes considered as irregularities. These examples are several forms of otherwise regular preterites:
There are two kinds of changes that can affect stem vowels of some Spanish verbs: diphthongization and vowel raising. Both changes affect -e- or -o- in the last (or only) syllable of a verb stem. Diphthongization changes -e- to -ie-, and -o- to -ue-. Vowel raising changes the mid vowels -e- and -o- to the corresponding high vowels: -i- and -u- respectively. Some verbs, in their various forms, can exhibit both kinds of changes (e.g. , , (e-ie-i); , , ) (o-ue-u).
The identities of verbs that diphthongize -e- to -ie- and -o- to -ue- are not marked and must be learned individually. In a diphthongizing verb, the change occurs when the stem syllable is stressed, which in effect happens only in the singular persons and third-person plural of the present tense and in the imperative. In the other forms, including the infinitive, are stressed on their endings, not their stems. Exceptionally, the -u- of (u-ue -gar, -jugar) and the -i- of verbs derived from querer like (i-ie) also are subject to diphthongization ('; ').
Word-initially, *ie- is written ye- (' > ') (e-ie > ye) and *ue- is written hue- (' > ') (o-ue > hue, oler). Also, the -ue- diphthong is written -üe- after g, with the diaeresis to indicate that the letter is not silent (' > ') (reflexive, go-güe -zar).
The following table shows contrasting forms for both types diphthongization, and the irregular -quirir and jugar:
The verbs and also undergo vowel raising. Additional diphthongizing verbs include ' (o-ue), ' (e-ie), ' (o-ue), ' (-zar e-ie, -ezar), ' (o-ue), ' (e-ie), ' (o-ue), ' (o-ue, -morir), ' (o-ue), ' (o-ue), ' (o-ue, -poder), ' (o-ue), ' (e-ie, -querer), ' (o-ue), ' (e-ie-i), ' (e-ie, -tener, G-Verb), ' (e-ie, -venir, G-Verb), ' (o-ue), and ' (o-ue, -olver).
Many verbs with -e- or -o- in the root do not alternate. Common non-diphthongizing verbs include ', ', ', ', 'ò, ', ', ', ', ', ', ', ', ', ', ', 'ù, ', ', ', ', ', ', ', ', ', ', ', ', ', ', ', ', among others. Less frequent verbs of this kind are often a source of mistakes for children learning to speak, and also for some adults:
Vowel raising appears only in -ir verbs, and in this group it affects , , (an alternative of the more common ) and nearly all verbs which have -e- as their last stem vowel (e.g. , ). Exceptions to that last rule include ' and its derivatives, which are only diphthongizing.
The forms that exhibit the change can be described negatively as those in which the stem vowel is not diphthongized and the ending does not contain stressed i or the -ir- sequence. In other words, vowel raising affects the forms whose endings do not contain an i which is not part of a diphthong, taking into account that diphthongizing overrides vowel raising.
For diphthongizing verbs (e.g. , '), the vowel-raising forms are:
For non-diphthongizing verbs (e.g. ') it affects these same forms (pidamos, pidáis, pidiendo, pidió, pidieron, pidiera...), plus:
The forms which undergo neither diphthongizing nor vowel raising are:
Vowel-raising but not diphthongizing verbs include:
The following table demonstrates the contrasting forms for both types of raising, as well as the irregular decir and hacer.
Diphthongizing and vowel-raising verbs include:
The following table demonstrates the contrasting forms of both an e-ie-i verb and an o-ue-u verb, along with the irregular venir:
Diphthongs in the infinitive may be preserved throughout the conjugation or broken in the forms which are stressed on the stem, depending on whether the i or u in contact with a/e/o take the stress or not. The stressed vowel is marked bold in the examples: ' > cambio, but ' > envÃÂo (requiring an acute accent to indicate the resulting hiatus). The Real Academia Española does not consider either behaviour as irregular, but illustrates each with six "regular" models, one for each possible diphthong in the infinitive: ', ', ', ', ' and ' for diphthong-keeping verbs and ', ', ', ', ' and ' for diphthong-breaking ones. The presence of a silent h does not break a diphthong, so a written accent is needed anyway in rehúso.
All verbs ending in -guar are diphthong-keeping, as well as ', ', ' and '. Two diphthongs are kept in ' > desahucio (again the -h- makes no difference), which thus follows both the anunciar and causar models.
Diphthong-breaking verbs include ', ', ', ', ', ', ', ', ', ', ', '. The verbs ', ', ', ' and ' are also diphthong-breaking (crÃÂo, guÃÂe), but when the stress falls on the endings the resulting forms are generally considered as monosyllables and thus written without accent: crie, fie, guiais, lieis.... In spite of that, the regular accentuation rules can also be used if they are pronounced as bisyllabic: crié, guiáis....
For the verbs ' and ' both options are valid: adecuo or adecúo.
The ui diphthong in ' is kept throughout the conjugation despite the fact of the i getting the stress in forms such as cuido (written without stress mark).
In er and ir verbs, the first person singular of the present indicative and the whole present subjunctive are the only forms whose endings start with o/a instead of e/i. These two different phonetic environments made Latin forms evolve differently in many verbs, leading to irregularities. Whenever the first person singular of the present indicative has an irregularity other than diphthongizing, but still ends in -o, the whole present subjunctive shares that same irregularity. For example:
When the first person singular of the present indicative does not end in -o, the present subjunctive is also irregular, but in a different way:
Before o (in the first person singular of the indicative present tense) and a (that is, in all persons of the present subjunctive), the so-called g-verbs (sometimes "go-yo verbs", "yo-go verbs", or simply "go verbs") add a medial -g- after l and n (also after s in asir), add -ig- when the root ends in a vowel, or substitute -c- for -g-. This change overrides diphthongization (tener, venir) but combines with vowel-raising (decir). Many of these verbs are also irregular in other ways. For example:
This group of verbsâÂÂwhich originated in the Latin inchoative verbs but now includes other verbs as wellâÂÂsubstitute -zc- for stem-final -c- before o and a. The group includes nearly all verbs ending in -acer (except ' and derived verbs), -ecer (except ' and '), -ocer (except ' and derived verbs), and -ucir. For example:
Yacer may alternatively be conjugated with -zc- ('), -g- ('), or a compromise -zg- (').
Some -er and -ir verbs (most g-verbs plus , ', ', ' and ') also change their stem in the future and conditional. This involves syncope:
Many of these verbs also have shortened tú imperative forms (apocope): decir â ', hacer â ', salir â ', poner â ', tener â ', venir â '. However, all verbs derived from decir are regular in this form: bendice, maldice, desdÃÂcete, predice, contradice.
Some verbs (including most g-verbs and most verbs ending in ) have a somewhat different stem in the preterite. These stems are very old and often are found in Latin as well. The same irregular stem is also found in the imperfect subjunctive (both in -ra and -se forms) and the future subjunctive. These stems are anomalous also because:
Examples:
The verb in modern Spanish has a regular -er verb preterite (yo vi, tú viste, él vioâÂÂnote the lack of written accent on monosyllables), but in archaic texts the irregular preterite forms yo vide, él vido, etc. are sometimes seen.
A number of verbs have irregular past participles, sometimes called "strong" because the change is in the root, rather than an ending. This includes verbs which are irregular in many other ways, like ' and ', but for other verbs this is their only irregularity (such as ' and '), while some very irregular verbs (such as ' and ') have regular past participles. Examples:
Most of these verbs have derivatives with the same irregularity. For example, alongside volver â vuelto and poner â puesto, there are ' â ' and ' â '; alongside ' â ' there is ' â ' (but note ' â ', ' â ' are regular, though they also have the adjectival forms ' and '). Solver is obsolete, but its derivatives ' and ' (', ') are in common use. Likewise with and its derivatives comprimir, , , , , , and . The alternative form of escrito, ', is used in Argentina, Paraguay, and Uruguay; likewise with derivates of escribir, such as '.
There are verbs that have both a regular and an irregular past participle. Both forms may be used when conjugating the compound tenses and the passive voice with the auxiliary verbs ' and ', but the irregular form is generally the only one used as an adjective:
A number of other "strong" past participles, such as ', ', ', among others are obsolete for general use, but are occasionally used in Spain (and to a much lesser extent in Spanish America) among educated, style-conscious writers, or in linguistic archaisms such as proverbs (refranes). Otherwise, they are obsolete or solely used as adjectives.
The verbs "to go" and "to be [in essence]" both exhibit irregularities in the present, imperfect and preterite forms. Together with "to see", they are the only three verbs with irregular indicative imperfect past tenses. These verbs are highly irregular based on being single-syllable stems, and suppleting several tenses. Similarly, "to give" and "to be [in a state]" (whose stem was originally st-) also come from verbs with one syllable in the stem but they do not supplete any tenses. A table of their conjugations is shown below:
Whenever the stem of the indicative perfect past tense is irregular, the subjunctive past tense (-ra or -se) and the obsolescent subjunctive future tense (-re) share the same irregularity but with different infixes. The subjunctive past -ra forms are used in the table above, as the -se forms are less predominant. Some forms of and take an accent when marking stress would be redundant to distinguish them from unrelated words; such as contrasting with the prepositon . In New Mexican Spanish, may be replaced by .