The Four Conjugations

Verbs are classed in Four Regular Conjugations, distinguished by the stem-vowel which appears before -re in the Present Infinitive Active:—

The Principal Parts of a verb, showing the three stems which determine its conjugation throughout, are—

1. The Present Indicative (as, amō), showing the Present Stem.
2. The Present Infinitive (as, amā-re), showing the Present Stem.
3. The Perfect Indicative (as, amāv-ī), showing the Perfect Stem.
4. The neuter of the Perfect Participle (as, amāt-um), or, if that form is not in use, the Future Active Participle (amāt-ūrus), showing the Supine Stem.

The regular forms of the Four Conjugations are seen in the following:—

First Conjugation:—

1. Active, amō, amāre, amāvī, amātum, love.
2. Passive, amor, amārī, amātus.
3. Present Stem amā-, Perfect Stem amāv-, Supine Stem amāt-.

Second Conjugation:—

1. Active, dēleō, dēlēre, dēlēvī, dēlētum, blot out.
2. Passive, dēleor, dēlērī, dēlētus.
3. Present Stem dēlē-, Perfect Stem dēlēv-, Supine Stem dēlēt-.

In the Second conjugation, however, the characteristic ē- rarely appears in the perfect and perfect participle. The common type is, therefore:—

1. Active, moneō, monēre, monuī, monitum, warn.
2. Passive, moneor, monērī, monitus.
3. Present Stem monē-, Perfect Stem monu-, Supine Stem monit-.

Third Conjugation:—

1. Active, tegō, tegĕre, tēxī, tēctum, cover.
2. Passive, tegor, tegī, tēctus.
3. Present Stem tegĕ-, Perfect Stem tēx-, Supine Stem tēct-.

Fourth Conjugation:—

1. Active, audiō, audīre, audīvī, audītum, hear.
2. Passive, audior, audīrī, audītus.
3. Present Stem audī-, Perfect Stem audīv-, Supine Stem audīt-.

In many verbs the principal parts take forms belonging to two or more different conjugations (cf. § 189):—

1. 1, 2, domō, domāre, domuī, domitum, subdue.
2. 2, 3, maneō, manēre, mānsī, mānsum, remain.
3. 3, 4, petō, petĕre, petīvī, petītum, seek.
4. 4, 3, vinciō, vincīre, vīnxī, vīnctum, bind.

Such verbs are referred to the conjugation to which the Present sten conforms.

The parent (Indo-European) speech from which Latin comes had two main classes of verbs:—

1. Thematic Verbs, in which a so-called thematic vowel (e/o, in Latin i/u) appeared between the root and the personal ending: as, leg-i-tis (for †leg-e-tes), leg-u-nt (for †leg-o-nti).

2. Athematic Verbs, in which the personal endings were added directly to the root: as, es-t, es-tis (root ES)

   , dă-mus (dō, root DA), fer-t (ferō, root FER).

Of the Athematic Verbs few survive in Latin, and these are counted as irregular, except such as have been forced into one of the four “regular” conjugations. Even the irregular verbs have admitted many forms of the thematic type.

Of the Thematic Verbs a large number remain. These may be divided into two classes:—

1. Verbs which preserve the thematic vowel eor o (in Latin i or u) before the personal endings.—These make up the Third Conjugation. The present stem is formed in various ways (§ 176), but always ends in a short vowel e/o (Latin i/u). Examples are tegō (stem (tege/o-), sternimus (stem (sterne/o-) for †ster-no-mos, plectunt (stem (plecte/o-) for †plec-to-nti. So nōscō (stem (gnōsce/o-) for gnō-sc-ō. Verbs like nōscō became the type for a large number of verbs in -scō, called inceptives (§ 263. 1).
2. Verbs which form the present stem by means of the suffixye/o-, which already contained the thematic vowele/o.—Verbs of this class in which any vowel (except u) came in contact with the suffix ye/o-suffered contraction so as to present a long vowel ā-, ē-, ī-, at the end of the stem. In this contraction the thematic e/o disappeared. These became the types of the First, Second, and Fourth conjugations respectively. In imitation of these long vowel-stems numerous verbs were formed by the Romans themselves (after the mode of formation had been entirely forgotten) from noun- and adjective-stems. This came to be the regular way of forming new verbs, just as in English the borrowed suffix -ize can be added to nouns and adjectives to make verbs: as, macadamize, modernize.

Thematic verbs of the second class in which a consonant or u came into contact with the suffix ye/o- suffered various phonetic changes. Such verbs fall partly into the Third Conjugation, giving rise to an irregular form of it, and partly into the Fourth, and some have forms of both. Examples are:—(cōn) spiciō (-spicĕre) for †spekyō; veniō (venīre) for † (g) vem-yō; cupiō, cupĕre, but cupīvī; orior, orĭtur, but orīrī. Note, however, pluō (pluere) for †plu-yō; and hence, by analogy, acuō (acuere) for †acu-yō.

In all these cases many cross-analogies and errors as well as phonetic changes have been at work to produce irregularities. Hence has arisen the traditional system which is practically represented in §§ 175, 176.

The Present Stem may be found by dropping -re in the Present Infinitive:—

1. amā-re, stem amā-; monē-re, stem monē-; tegĕ-re, stem tegĕ-; audī-re, stem audī-.

The Perfect Stem is formed as follows:—

The suffix v (u) is added to the verb-stem: as, vocā-v-ī, audī-v-ī; or to the root: as, son-u-ī (sonā-re, root SON), mon-u-ī (monē-re, MON treated as a root).

The suffix s is added to the root: as, carp-s-ī (CARP), tēx-ī (for tēg-s-ī, TEG).

The root is reduplicated by prefixing the first consonant—generally with ĕ, sometimes with the root-vowel: as, ce-cid-ī (cadō, CAD), to-tond-ī (tondeō, TOND).

The root vowel is lengthened, sometimes with vowel change: as, lēg-ī (lĕg-ō), ēm-ī (ĕm-ō), vīd-ī (vĭd-e-ō), fūg-ī (fŭg-i-ō), ēg-ī (ăg-ō).

Sometimes the perfect stem has the same formation that appears in the present tense: as, vert-ī (vert-ō), solv-ī (solv-ō).

Sometimes the perfect is formed from a lost or imaginary stem: as, petī-v-ī (as if from †peti-ō, †petī-re, PET).

The Supine Stem may be found by dropping -um from the Supine. It is formed by adding t (or, by a phonetic change, s)—

To the present stem: as, amā-t-um, dēlē-t-um, audī-t-um.

To the root, with or without ĭ: as, cap-t-um (capiō, CAP), moni-t-um (moneō, MON used as root), cās-um (for †cad-t-um, CAD), lēc-t-um (LEG).