Defective verb

In linguistics, a defective verb is a verb with an incomplete conjugation. Defective verbs cannot be conjugated in certain tenses, aspects, or moods.

Arabic

In Arabic, defective verbs are called أفعال جامدة (lit., solid verbs). These verbs do not change tense, nor do they form related nouns. A famous example is the verb ليس laysa, which translates as it is not, although it is not the only sister of Kaana which exhibits this property: some Arabic grammaticians argue that دام "daama" (when one of the sisters) is also completely defective; those who refute this claim still consider it partially defective. Some other partially defective verbs are "fati'a" and "zaala," which have neither an imperative form nor an infinitive form when sisters of Kaana.

English

The most commonly recognized defective verbs in English are the class of preterite-present verbs — can/could, may/might, shall/should, must, ought to, and will/would (which was not historically a preterite-present but has joined the class in modern English). Though these verbs were not originally defective, in most varieties of English today, they occur only in a modal auxiliary sense. However, unlike normal auxiliary verbs, they are not regularly conjugated in the infinitive mood. Therefore, these defective auxiliaries do not accept each other as objects. Additionally, they do not regularly appear as participles. The defective form "ought to" is used with a "bare infinitive" verb, since the "to" goes with "ought," and not with the verb.

For example, can lacks an infinitive, future tense, participle, imperative, and gerund. The missing parts of speech, however, can be expressed by using the appropriate forms of to be plus able to. So, while I could do it and I was able to do it are equivalent, one cannot say *I will can, *I have canned, or *canning do it, but would still be able to say I will be able to, I have been able to, and being able to do it. Likewise, the role of must, which has only a present tense, can be filled in by to have plus to. This way, one can say things like he will have to clean the room next week and he had to clean the room last week, which would be impossible to do with must.

Some verbs are becoming more defective as time goes on; for example, although might is etymologically the past tense of may, it is no longer generally used as such (*he might not pass for "he was forbidden to pass"). Similarly, should is no longer used as the past of shall, but with a separate meaning indicating possibility or advice. (However, the use of the preterite form should as a subjunctive form continues, as in If I should go there tomorrow, ..., which contrasts with the indicative form I shall go there tomorrow.) The defective verb ought was etymologically the past tense of owe (the affection he ought his children), but it has since split off, leaving owe as a non-defective verb with its original sense and a regular past tense (owed).

Beyond the modal auxiliaries, beware is a full-fledged defective verb of English: it is used as an imperative (Beware of the dog) and an infinitive (I must beware of the dog), but very rarely or never as a finite verb, especially with inflectional endings (*bewared, *bewares). Another defective verb is the archaic quoth, a past tense which is the only surviving form of the verb quethe, "to say" (related to bequeath). Certain other verbs are defective only in specific constructions.

Impersonal verbs in English

Impersonal verbs such as rain and snow share some characteristics with the defective verbs in that conjugations such as I rain or they snow are not often found; however, the crucial distinction is that impersonal verbs are "missing" certain forms for semantic reasons — in other words, the forms themselves exist and the verb is capable of being fully conjugated with all its forms (and is therefore not defective) but some forms are unlikely to be found because they appear meaningless or nonsensical.

Nevertheless, native speakers can typically use and understand metaphorical or even literal sentences where the "meaningless" forms exist, such as:

• I rained on his parade.

Contrast the impersonal verb rain (all the forms exist even if they sometimes look semantically odd) with the defective verb can (only I can and I could are possible). In most cases, a synonym for the defective verb must be used instead (i.e. "to be able to"). (The forms with an asterisk (*) are impossible.)

I rain		I can		I am able to
I rained		I could		I was able to
I am raining		*I am canning		I am being able to
I have rained		*I have could		I have been able to
to rain		*to can		to be able to

French

falloir ("to be necessary", only the third-person forms with il exist; the present indicative conjugaison (il faut) is certainly the most oftenly used form of a defective verb in French), braire ("to bray", infinitive, present participle and third-person forms only), frire ("to fry", lacks non-compound past forms; speakers paraphrase with equivalent forms of faire frire), clore ("to conclude", lacks an imperfect conjugation, as well as first and second person plural present indicative conjugations), and impersonal weather and similar verbs as in English

Spanish

Abolir (forms such as *abuelo, for example);

Polish

widać ("it is evident"), słychać ("it is audible") (the only form of these verbs that exists is the infinitive)

Portuguese

A large number of Portuguese verbs are defective in person, i.e., they lack the proper form for one of the pronouns in some tense. The verb colorir ("to color") has no first-person singular in the present (thus requiring a paraphrase, like estou colorindo ("I am coloring") or the use of another verb of similar meaning, like pintar ("to paint").

Russian

The verb победить ("to win") does not have a future form of the first person singular, so the phrase "I will win" cannot be translated into Russian directly word for word.

Swedish

The auxiliary måste (must) lacks the infinitive, except in Swedish dialects spoken in Finland. Also, this verb is unique in having identical present and past tense forms. The verb stinga (sting) lacks the past tense, but the synonym sticka can be used in stead.

Korean

말다 (to stop or desist) may only be used in the imperative form, after an 'action verb + 지' construction. Within this scope, however it can conjugate for different levels of politeness; e.g. 하지마! (Stop that!); 하지마십시오 ('Please, don't do that').

Irish

Arsa (says/said), can only be used in past or present tenses. Copula is lacks a future tense, imperative mood and conditional mood.

Hungarian

Some verbs have no imperative form, e.g. csuklik (hiccup).

Welsh

Welsh has a handful of defective verbs, a number of which are archaic or literary. Some of the more common ones in everyday use include dylwn (I should/ought) with only imperfect and pluperfect, meddaf (I say) in the present and imperfect and geni (to be born) which has a verb-noun and impersonal forms, e.g. Ganwyd hi (She was born).

Latin

Latin has defective verbs that possess forms only in the perfect system; such verbs have no present tense forms whatsoever. However, these verbs are present in meaning. For example, the first-person form odi and infinitive odisse appear to be the perfect of a verb such as *odo/odio, but in fact have the present-tense meaning "I hate". Similarly, the verb memini, meminisse is conjugated in the perfect:

meminī

meministī

meminit

meminimus

meministis

meminērunt

Instead of "I remembered", "you remembered", etc., these forms signify "I remember", "you remember", etc. Latin defective verbs also possess regularly formed pluperfect forms (with a simple past tense meaning) and future perfect forms (with a simple future tense meaning). Compare deponent verbs, which are passive in form and active in meaning.

The verb coepī, coepisse, which means "to have begun" or "began", is another verb that lacks a present tense system, but it does not have present meaning. Instead, the verb incipiō, incipere is used in the present tense. This is not a case of suppletion, however, because the verb incipere can also be used in the perfect.

The verbs inquit and ait, both meaning "said", cannot be conjugated through all forms.

See also

• Unpaired word – other form of lexical gap