Some Notes on the Perfect Tense in Greek
The Perfect Tense in Greek, unlike in Latin, is always a true Perfect and cannot do duty for the Simple Past (i.e. the Aorist). It represents an action as already completed at the present time, such as in the sentence την εἰρηνην σεσωκα, ‘I have saved the peace’. This sentence can never be translated ‘I saved the peace’ (for that would imply nothing as to the completion of the action).
Because the Perfect, although implying the performance of the action in past time, states only that the action stands completed at the present time, it is classified with the Present and Future among the Primary Tenses.
Certain Perfect forms in Greek can be translated as Present, for instance οἰδα, meaning ‘I know’ (lit. ‘I have seen’), is the Perfect tense of the obsolete verb εἰδω, meaning ‘I see’; and while γιγνομαι (Present) means ‘I become’, its Perfect γεγονα means ‘I am’ (lit. ‘I have become’).
If we combine the concept of Aspect with that of Tense, we could call the Perfect Tense the Present Perfective, the Present embodying the concept of Tense (or time) and the Perfective embodying the concept of Aspect (i.e. the degree of completion). It is imperative to bear the concept of Aspect in mind when translating non-finite parts of the Verb, such as Participles. The Perfect Participle is much rarer than the Aorist Participle in Greek, but where it does occur it conveys a sense of completion and acts as a bridge between the past and the present. For instance, the sentence γιγνωσκω ἡττημενος means ‘I know that I have been defeated’; in other words, it brings the sense of defeat into the present. The Aorist Participle, on the other hand, i.e. γιγνωσκω ἡττηθεις, would leave the sense of defeat in the past and would be rendered ‘I know that I was defeated’.
The Perfect is known as the stuttering tense because it reduplicates the initial consonant of the Verb so that, for instance, παυω (powo) ‘I stop’ becomes πεπαυκα (pepowka) ‘I have stopped’. It is important to remember that Verbs which begin with a vowel, a double consonant (ζ, ξ, or ψ) or successive consonants other than a mute and a liquid are reduplicated by use of the augment. Therefore, for instance, the Perfect of the Verb ἀγγελλω (‘I announce) is ἠγγελκα (‘I have announced’). Crucially, the augment at the beginning of the Perfect is not a signifier of Tense and therefore does not have to be removed when forming non-finite parts of the Verb, such as Infinitives and Participles, neither of which are subject to Tense (being subject to Aspect instead). To take the example of ἀγγελλω, we have the following:
Perfect Tense (active): ἠγγελκα (‘I have announced’)
Perfect Participle (active): ἠγγελκως, ἠγγελκυια, ἠγγελκος
Perfect Infinitive (active): ἠγγελκεναι
These forms should be contrasted with those of the Aorist, where the augment is a signifier of Tense and must therefore be removed for the non-finite parts of the Verb:
Aorist Tense (active): ἠγγειλα (‘I announced’)
but
Aorist Participle (active): ἀγγειλας, ἀγγειλασα, ἀγγειλαν
Aorist Infinitive (active): ἀγγειλαι
Have I made myself clear?