Principal parts of the Latin verb
From Hull AWE
Here, for example, are the four principal parts of the verb amāre, ‘to love’:
- amo, ‘I love’ (the first person of the present indicative). The stem of this part of the verb, i.e., am-, is the stem of the present, imperfect and future tenses active and passive, indicative and subjunctive, and of the present participle active, amans (‘loving’).
- amāre, ‘to love’ (the active infinitive). The penultimate vowel of the infinitive indicates the conjugation to which the verb belongs and therefore the appropriate inflectional endings necessary to conjugate it. (There are four conjugations in Latin – verbs which, like amo, have an infinitive in -āre belong to the first conjugation; those with an infinitive ending in –ēre (e.g., monēre, ‘to advise’) belong to the second conjugation; those with an infinitive ending in –ĕre (e.g., regĕre, ‘to rule’) belong to the third conjugation; and those with an infinitive ending in –īre (e.g., audīre, ‘to hear’) belong to the fourth conjugation.)
- amāvi, ‘I have loved’ (the first person singular of the perfect indicative).The stem of this part of the verb, i.e., amāv-, is the stem of the perfect, pluperfect, and future perfect tenses active, indicative and subjunctive.
- amātum (the supine). The stem of the supine, i.e., amāt-, is the stem of the past participle passive, amātus (‘having been loved’), which is used to form perfect, pluperfect, and future perfect tenses passive, indicative and subjunctive. The stem is also the stem of the future participle active, amāturus, (‘being about to love’). (The supine is a verbal noun, the accusative of a fourth declension noun ending in –us. It is not common in Classical Latin, though sometimes used after verbs of motion to express purpose, as in Marcus venatum ire volebat (‘Marcus wanted to go hunting’), or Venit panem venditum (‘He came to sell bread’) There is also an ablative form of the supine ending in –u, which is used with some adjectives to indicate respect or point of view, as in such phrases as mirabile dictu (‘amazing to say') and facilis factu (‘easy to do').