# Latin/Lesson 5-Perfect Indicative
## Latin Perfect Active Tense

The perfect tense is used for action that has already been completed. English has two corresponding constructions: present perfect and simple past. The present perfect uses the present of "to have" plus the past participle. ("I have sailed to Athens twice." "These women have spoken the truth.") The simple past is a separate verb form that indicates a completed action. ("I came, I saw, I conquered.") Another related form, which uses "did" as an auxiliary, is used for emphasis, negation or interrogation. ("I did see you at the Forum, didn't I?")
In Latin, the perfect indicative is equivalent to all of these.
The perfect endings:
| Person | Singular | Plural |
| 1st | -ī (egō) | -imus (nōs) |
| 2nd | -istī (tū) | -istis (vōs) |
| 3rd | -it (is/ea/id) | -ērunt $^{(1)}$ (eī/eae/ea) |
$^{(1)}$ There is an alternative third person plural ending, -ēre, used mainly in poetry. For example, amāvēre = amāvērunt.
Although these endings apply to all Latin verbs, each verb's stem changes differently in the perfect tense. To find the stem, use the third principal part, which is the first person singular perfect active indicative form of that verb.
* To conjugate the perfect present, attach the personal ending to the perfect stem.

### Example

* amō, amāre, amāvī, amātum; to love, like
    Note that amāvī is the first person singular perfect active indicative. Drop the -ī to get the stem, which is amāv-, then add personal endings.
Singular:
    amāv- + -ī = amāvī (I have loved.)
    amāv- + -istī = amāvistī (You have loved.)
    amāv- + -it = amāvit (He/She/It has loved.)
Plural:
    amāv- + -imus = amāvimus (We have loved.)
    amāv- + -istis = amāvistis (You have loved.)
    amāv- + -ērunt = amāvērunt (They have loved.)
Basically, the Perfect indicative active is the perfect tense under a flash name.

## Rules for Finding the Perfect Stem

The perfect stem can often be guessed by knowing the verb's first person singular and infinitive. Here are some rules that perfect stems often follow.
Conjugation in the Perfect tense :
| Conjugation | Perfect First Person Singular | Perfect First Person Singular | Perfect First Person Singular | Notes |
| 1st (-are) | -avi | -i | -edi | -avi is used for the overwhelming majority of verbs. Exceptions include iuvare and lavare (iuvi, lavi) and dare (dedi). |
| 2nd (-eo, -ere): | -ui | -i | -si | -ui is the most common but much less so than -avi in the first conjugation. Some verbs, like videre and sedere, become vidi and sedi. . For the -si rule, the letter d at the end of the stem, if present, is dropped and cs and gs compound into x (eg. rideo -> ridsi -> risi). |
| 3rd (-o, -ere): | -i | -si | -idi | Many verbs, like defendere, keep the same perfect stem, so the first person perfect singular becomes defendi. This can create tense ambiguity in the third person singular and first person plural (defendit, defendimus). The -si rule follows the same conventions as the 2nd conjugation(eg. ludere -> ludsi -> lusi, regere -> regsi -> rexi). The -idi rule is used with compounds of dare, which are all third conjugation (eg. reddere -> reddidi, credere -> credidi) |
| mixed (-io, -ere): | -i | -ivi | -si | For the -i rule, the last vowel in the stem is often changed to e (eg. capere -> cepi, facere -> feci). For the ivi rule, the stem is unchanged (eg. cupere -> cupivi). For the -si rule, just like in the 3rd conjugation, cs and gs compound into x and the changing vowel rule also applies (eg. conspicere -> conspexi). |
| 4th (-io, ire) | -ivi | -ui | | Fairly straightforward. eg. audire -> audivi, aperire -> aperui |
| ire (irreg.) | -ii | | | All ire compounds (eg. transire, redire, inire) follow this rule. |
| esse (irreg.) | fui | | | The perfect of esse is fui, some verbs in the esse family change the perfect slightly (eg. abesse -> afui, posse -> potui) |