No, defective verbs in Spanish aren't verbs that are broken. But they are verbs that are different than others in that some or even most of the normal conjugated forms either don't exist or are seldom used.
There are three reasons why defective verbs, known in Spanish as verbos defectivos, might not have or use all conjugated forms. Here they in order of how "defective" they are:
Verbs Where Not All Conjugated Forms Exist
Spanish has a handful of verbs that some authorities indicate don't exist in all conjugations, although there is no apparent logical reason why they wouldn't. The most common of these is abolir ("to abolish"), which some grammar guides and dictionaries say is conjugated only in forms where the suffix begins with -i. (The illegitimate forms include most present-tense conjugations and some commands.) Thus, for example, according to these authorities, abolimos ("we abolish") is a legitimate conjugation, but abolo ("I abolish") is not.
These days, however, the full conjugation of abolir is recognized by the Royal Spanish Academy, so there's no real need to avoid using any particular conjugated form.
Three other verbs that traditionally weren't conjugated without endings beginning with -i are agredir ("to attack"), balbucir ("to babble"), and blandir ("to brandish").
Additionally, a few uncommon verbs are used rarely, if at all, in forms other than the infinitive and past participle. The most common of these are:
- aterirse (to be freezing stiff)
- despavorir (to be terrified)
- desolar (to destroy)
- empedernir (to petrify, to harden)
Finally, soler (a verb that has no direct equivalent in English but is roughly translated as "to be usually") is not conjugated in the conditional, future, and (according to some authorities) preterite tenses.
Verbs Logically Used Only in the Third-Person Singular
Some verbs of weather and similar natural phenomena are impersonal verbs, meaning that they don't have a noun or pronoun performing the action. They are used only in the third-person singular and are typically translated to English using using the dummy pronoun "it" as their subject. Among the most common of these are:
- amanecer (to dawn)
- anochecer (to get dark outside)
- helar (to freeze)
- granizar (to hail)
- llover (to rain)
- nevar (to snow)
- relampaguear (to flash lightning)
- tronar (to thunder)
Note that three of these verbs can be conjugated when have meanings other than those given above: Amanecer can be used to mean "awaken." Anochecer can be used to refer actions that occur at dusk. And relampaguear can be used for flashes other than those from lightning.
Very rarely, these verbs may be used in a personal or figurative sense in other than the third person. But it would be much more common to speak of these weather phenomenon using hacer. If one were, for example, anthropomorphizing Mother Nature and she were speaking in the first person, it would be more common to use an expression such as hago nieve (literally, "I make snow") rather than coining a first-person construction of nevar.
Gustar and Other Verbs Used in the Same Way
Gustar and several other verbs are frequently used in sentences where they are used in third person while preceded by an object and followed by the verbs subject. An example is the sentence "Me gustan las manzanas" for "I like apples"; typically the word that is the subject in the English translation becomes the indirect object of the Spanish verb.
Other verbs used this way include:
- doler (to cause pain)
- encantar (to enchant)
- faltar (to be insufficient)
- importar (to matter)
- parecer (to seem)
- quedar (to remain)
- sorprender (to surprise).
These verbs aren't true defective verbs, because they exist in all conjugations, even though they are most common in the third person. The way they are used also doesn't seem to be particularly unusual to native Spanish speakers; they tend initially to be confusing to English speakers learning Spanish because of the way they are translated.
- Defective verbs in Spanish are those that don't have all conjugated forms, or that some of the conjugated forms are seldom used.
- Some of the weather verbs are irregular because they are used only in the third-person singular, while there are also few verbs that are missing some conjugated firms for no clear reason.
- Verbs such as gustar that are used primarily in the third person followed by their subject are sometimes thought of as defective verbs because their use in the first and second persons is uncommon.