irreguler verb

In contrast to regular verbs, irregular verbs are those verbs that fall outside the standard patterns of conjugation in the languages in which they occur.

What counts as an irregular verb is strongly dependent on the language itself. In English, the surviving strong verbs are considered irregular. In Old English, by contrast, the strong verbs are usually not considered irregular, at least not only by virtue of being strong verbs: there were several recognised classes of strong verbs, which were regular within themselves.

In Latin, similarly, most verbs outside the first or fourth conjugations have three principal parts, which form part of the lexicon and must be learned. The three principal parts are the present tense stem, the perfect tense stem, and the past participle; a variety of inflections, ablaut, and sometimes reduplication are used to form these parts. For example, the principal parts of spondeo ("I promise") include spopondi ("I promised"), showing reduplication, and sponsus ("promised"); these forms cannot be predicted from the present stem, but when you know all three, the entire system can be constructed from these three parts by rule. This verb is not usually considered irregular in Latin. Latin also exhibits deponent verbs, inflected in the passive voice alone; and defective verbs, missing some principal parts. Truly irregular verbs in Latin are a rather small class; they include esse ("to be"); dare and its derivatives ("to give"); êsse ("to eat"); ferre and its derivatives ("to carry"); velle and its derivatives ("to wish"); ire and its derivatives ("to go"); and fieri ("to become"). Most irregular Latin verbs are themselves vestiges of the athematic conjugations of Indo-European, a surviving (and regular) group found in Greek.

Greek and Sanskrit show even greater complexities, with widely different thematic and athematic inflection sets; which set goes with which verb stem cannot be predicted by rule. In languages of this type, these variations are not usually enough to label a verb "irregular". They instead form a part of the lexicon; when a verb is learned, the various patterns used to conjugate it must also be learned.

By contrast, in modern English, the strong verbs are largely a closed and vestigial class. (Analogy has created a few new strong verbs, such as dive.) All of the surviving strong verbs differ markedly from other verbs, and thus are classified as "irregular"; here, they are conspicuous exceptions in the midst of a much larger class of rule-bound regular verbs.

In some languages, the count of irregular verbs could be greatly expanded if one were to count verbs that are irregular only in their spelling, but not in their pronunciation. For example, in Spanish, the verb rezar ("to pray") is conjugated in the present subjunctive as rece, reces, rece, etc. The substitution of c for z does not affect the pronunciation. It is strictly a matter of orthography. Therefore, this verb is not normally considered irregular.

Other issues affecting the count of irregular verbs in various languages are:

* How many patterns of conjugation are considered standard. If a large enough group of irregular verbs in a language have parallel conjugations, it is arbitrary whether to count that as an additional "standard" conjugation or as a large collection of irregular verbs.
* Which verbs are to be counted as separate, rather than merely prefixed. For example, in English, to withhold conjugates exactly like to hold, and in Spanish, detener ("to detain") conjugates exactly like tener ("to have"). In each case, are these to be counted as two separate irregular verbs, or as a single irregular verb, with and without a prefix?

[edit] Number of irregular verbs in different languages

While the term "irregular verb" is not precisely enough defined to allow a definitive count of the irregular verbs in all languages, the following table is illustrative of how much this phenomenon varies across languages.
Language Count[citation needed] Notes
Latin 924
Italian over 400
German 181
English 178 see Wiktionary appendix: Irregular English verbs
Danish 131
French 81
Swedish 76
Dutch 55
Spanish 46 see Spanish irregular verbs
Welsh 11
Finnish ≤4 + 4 Only the verb olla "to be" has one truly irregular ending (added with some consonant assimilation), and a few verbs have rare consonant elision patterns warranting memorizing them. For example, juoks+en "I run" elides 'k' to give juos+ta "to run", and näh+dä "to see" elides 'h' to give nä+en "I see". Spoken Finnish has further irregularity on the verb "to be" (oo- pro ole-, also occasionally o pro on), and four additional irregular verbs (tuu "come", mee "go", paa "put", nää "see").
Japanese ≤5 する suru "to do", 来る kuru "to come", 行く iku "to go", ある aru "to exist (inanimate)", and くれる kureru "to give (to the in-group)" are irregular. There are also several categories of verbs with either a very small number of members (the five honorific verbs), or conjugations based on multiple stems (aisuru and aisu "to love" are used interchangeably but the former is not used in certain forms such as the imperative *aishiro); these are considered by some authorities irregular and by others not.
Ukrainian ≤3 Бути (to be), їсти (to eat), давати (to give) are the only irregular "basic" verbs. Also, бути is irregular in that sense that it withstands inflection except for when forming infinitive (бути (inf.) — є (non inf.)). Though the actual number of irregular verbs may be considered to be much higher since language's synthetic nature allows to make complex verbs based on these.
Latvian 3 these 3 verbs are būt, iet, dot
Chinese 1 有 yǒu forms its negative with 没 méi rather than with 不 bù in Mandarin and has a separate negative form 冇 mou in Cantonese
Northern Sami 1 Only the verb leat "to be" is irregular; all others are conjugated regularly.
Quechua 1 Only the verb kay "to be" is irregular.
Turkish 0 -
Interlingua 0 While Interlingua has no true irregular verbs, it has three short verb forms: es ("is", "am", "are"), ha ("have", "has"), and va ("go", "goes"). These forms are optional but widely used. Interlingua also has a few alternate forms of esser ("to be"), such as sera for essera ("will be"). These alternate forms differ from an irregular verb in that they are not a full conjugation. They are optional and rare.
Esperanto 0 (like most constructed languages)