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.
Orthographic changes 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: : c—qu: > (-car), > (-quir). : z—c: > (-zar), > (-cer). : g—j: > (-ger). But in verbs ending in -jar, the j is kept before e: > (not ). : g—gu: > (-gar), > (-guir). : gu—gü: > (-guar). Other predictable changes involve stress marks, i—y alternations and i-dropping, some of which are sometimes considered as irregularities. These examples are several forms of otherwise regular preterites: Stress mark on stressed i after a, e or o: > (-caer), > (-eer), > (-ír, -oír); this does not apply to any G-verbs such as and its related forms. Stress mark not used in monosyllabic forms: > , ; > , . However, before 2010, the forms and , and , and , and and could also be written with the accent mark by writers who pronounce these forms as bisyllabic.Diccionario panhispánico de dudas, "tilde"2. n.1.2. But this option was not available for . Unstressed i is written y between non-silent vowels: > , (-aer, -caer); > , (-uir). This does not apply to verbs ending in -quir (for example, > , ). Unstressed i is dropped between ll or ñ and a vowel: > (not *bullió) (-llir/-ñir), > (-ñer).
Stem-vowel changes 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).
Diphthongization 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: +Vowel diphthongizing verbs Verb yo tú vos él/ ella; usted nosotr(os/as) vosotr(os/as) ell(os/as); ustedes / pensando/ pensado indicative present pienso piensas pensás piensa pensamos pensáis piensansubjunctive presentpiensepiensespensés*piensepensemospenséispiensenimperative—piensa no piensespensá no pensés*pensad no pensáis / oliendo/ olido indicative present huelo hueles olés huele olemos oléis huelensubjunctive presenthuelahuelasoláshuelaolamosoláishuelanimperative—huele no huelasolé no olás*oled no oláis/ inquiriendo/ inquiridoindicative presentinquieroinquieresinquirísinquiereinquiremosinquirísinquierensubjunctive presentinquierainquierasinquirás*inquierainquiramosinquiráisinquieranimperative—inquiere no inquierasinquirí no inquirás*inquirid no inquieráis/ jugando/ jugadoindicative presentjuegojuegasjugásjuegajugamosjugáisjuegansubjunctive presentjueguejueguesjugués*jueguejuguemosjuguéisjueguenimperative—juega no jueguesjugá no jugués*jugad no juguéis* In Central America pensés, contés, etc. are used in the subjunctive present and imperative,Diccionario panhispánico de dudas, voseo, section 2.1.2.1.b but the Royal Spanish Academy prescribes pienses, cuentes, etc., as in Rioplatense Spanish.
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 , , , , ², , , , , , , , , , , , ¹, , , , , , , , , , , , , , , , , among others. Less frequent verbs of this kind are often a source of mistakes for children learning to speak, and also for some adults: → , instead of ,
Vowel raising 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.
Affected forms 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 iTerrell, Tracy D., and Salgués de Cargill, Maruxa, Lingüística aplicada a la enseñanza del español a anglohablantes (New York: Wiley, 1979), p. 97. 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: the first-person and second-person plural of the present subjunctive (sintamos, sintáis, durmamos, durmáis); the present active participle or gerund (sintiendo, durmiendo); the third-person indicative past perfect (sintió, sintieron, durmió, durmieron); all forms of the subjunctive imperfect past (sintiera/sintiese..., durmiera/durmiese...) and of the future subjunctive (sintiere..., durmiere...).
For non-diphthongizing verbs (e.g. ) it affects these same forms (pidamos, pidáis, pidiendo, pidió, pidieron, pidiera...), plus: the singulars and third person plural of the present indicative (pido, pides, pide, piden); the remaining forms of the present subjunctive (pida, pidas, pidan); the tú form of the imperative (pide), but not the vos nor vosotros forms.
The forms which undergo neither diphthongizing nor vowel raising are: the first-person and second-person plural of the indicative present (sentimos, sentís), because these forms have stressed i in their endings. the infinitive (sentir), past participle (sentido), indicative imperfect past (sentía...) and the vos and vosotros forms of the imperative (sentí, sentid), for the same reason. the future (sentiré...) and conditional (sentiría...), whose endings contain the -ir- sequence and derive from the infinitive.
Affected verbs Vowel-raising but not diphthongizing verbs include: those ending in -edir (, ...), -egir (, ), and -etir (, ) those ending in -eír (, , ). Double i that would result is simplified (, not nor ). The stressed i in contact with a/e/o must take an acute accent (río, ríe, ría); monosyllabic forms of the indicative perfect past tense do not have it (though it was officially allowed until 2010). those ending in -eñir (, ...). As usual, the unstressed i between ñ and a vowel is dropped (tiñendo, tiñó, tiñeron, tiñera...). and derived verbs (, ...), in forms that do not have overriding irregularities. . Usually diphthongizing (with ye- forms such as yergo), there are raised forms that are valid but rare (irgo). and derived verbs (-facer, like ), which goes from -a- to -i- in forms that do not have overriding irregularities. The -facer derivatives take forms identical to hacer but with an initial f- instead of an initial h-. . The affected forms are equal to those derived from the more usual infinitive , which is regular except in the past participle . and derived verbs (including ) The following table demonstrates the contrasting forms for both types of raising, as well as the irregular decir and hacer. +Vowel-raising verbsVerbyotúvosél/ ella; ustednosotr(os/as)vosotr(os/as)ell(os/as); ustedes-pidiendo-pedidoindicative presentpidopidespedíspidepedimospedíspidenindicative perfect pastpedípedistepidiópedisteispidieronsubjunctive presentpidapidaspidáspidapidamospidáispidansubjunctive pastpidierapidieraspidierapidiéramospidieraispidieranimperative—pide no pidaspedí no pidaspidapidamospedid no pidáispidan-pudriendo-podridoindicative presentpudropudrespodríspudrepodrimospodríspudrenindicative perfect pastpodrípodristepudriópodristeispudrieronsubjunctive presentpudrapudraspudrapudramospudráispudransubjunctive pastpudierapudieraspudierapudiéramospudieraispudieranimperative—pudre no pudraspodrí no pudraspudrapudramospodrid no pudráispudran-diciendo-dichoindicative presentdigodicesdecísdicedecimosdecísdicenindicative perfect pastdijedijistedijodijimosdijisteisdijeronsubjunctive presentdigadigasdigásdigadigamosdigáisdigansubjunctive pastdijeradijerasdijeradijéramosdijeraisdijeranimperative—di no digasdecí no digasdigadigamosdecid no digáisdigan-haciendo-hechoindicative presenthagohaceshacéshacehacemoshacéishacenindicative perfect pasthicehicistehicehicimoshicisteishicieronsubjunctive presenthagahagashagáshagahagamoshagáishagansubjunctive pasthicierahicierashicerahiciéramoshicieraishicieranimperative—haz no hagashacé no hagashagahagamoshaced no hagáishagan Diphthongizing and vowel-raising verbs include: those ending in (, , ...) and -ertir (, ...). those ending in (, , , ...), except . , , and and derived verbs (, ...), in the forms that do not undergo overriding irregularities. 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: +Vowel-raising and vowel-diphthongizing verbsVerbyotúvosél/ ella; ustednosotr(os/as)vosotr(os/as)ell(os/as); ustedes/ sintiendo/ sentidoindicative presentsientosientessentíssientesentimossentíssientenindicative perfect pastsentísentistesintiósentisteissintieronsubjunctive presentsientasientassentássientasentamossentáissientansubjunctive pastsintierasintierassintierasintiéramossintieraissintieranimperative—siente no sientassentí no sientassientasentamossentid no sentáissientan/ durmiendo/ dormidoindicative presentduermoduermesdormísduermedormimosdormísduermenindicative perfect pastdormídormistedurmiódormisteisdurmieronsubjunctive presentduermaduermasdormásduermadormamosdormáisduermansubjunctive pastdurmieradurmierasdurmieradurmiéramosdurmieraisdurmieranimperative—duerme no duermasdormí no duermasduermadormamosdormid no dormáisduerman/ viniendo/ venidoindicative presentvengovienesvenísvienevenimosvenísvienenindicative perfect pastvinevinistevinovinimosvinisteisvinieronsubjunctive presentvengavengasvengásvengavengamosvengáisvengansubjunctive pastvinieravinierasvinieraviniéramosvinieraisvinieranimperative—ven no vengasvení no vengasvengavengamosvenid no vengáisvengan
Diphthong loss