Irregular verbs in other languages
What counts as an irregular verb is strongly dependent on the language
itself. In English, the surviving strong verbs are considered irregular, largely because they are sui generis. 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"); Ísse ("to eat"); ferre and its derivatives ("to carry"); volo
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
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
- 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?
Number of irregular verbs in different languages
Thus 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.