The Aorists in Koine Greek (聖經希臘文的不定過去）

When used in grammar, Collins English dictionary defined "aorist" as: 

“a tense of the verb in classical Greek and in certain other inflected languages, indicating past action without reference to whether the action involved was momentary or continuous” 

The word "Aorist" originated from greek root aoristos (αόριστος), meaning “not limited”, from “a” and “horistos” restricted. 

The greek grammar is different from that of English in its lack of specificity as that of English in defining a past, present or future tense.  Aorist tense is generally referred as a past tense when translated into English.  However, it may not always be so. 

To change a verb from a present form to the aorist, there are two types of aorist inflections.  First aorist modifies the verb stem with additional augment, tense formative and secondary endings.  The second aorist also requires modification of the verb stem giving the so-called “aorist stem”, in contrast with the verb stem in present or imperfect forms as “present stem”.  

	Augment	Verb Stem	Tense Connectives	Secondary Endings (Active)	Secondary Ending (Middle)
First Aorist	ε	present stem	σα	ς	μην
Second Aorist	ε	aorist stem	ο	ν	μην
Imperfect	ε	present stem	ο	ν	μην

Specifically, verbs that takes the standard first aorist infection can have its verb form modified as shown in the table below: 

First Aorist	Augment +  Stem + Connecting Vowel + Secondary Active Endings ε + [ stem ] + [ σα ] + [secondary active endings]
		secondary active endings for singular	Examples	secondary active endings for plural	Examples
Aorist Active Indicative	First person	-	ἔλυσα	-μεν	ἐλύσαμεν
	Second person	-ς	ἔλυσας	-τε	ἐλύσατε
	Third person	-ε	ἔλυσε(ν)	-ν	ἔλυσα(ν)
Aorist Middle Indicable	First person	-μην	ἐλυσάμην	-μεθα	ἐλυσάμεθα
	Second person	-ω	ἐλύσω	-σθε	ἐλύσασθε
	Third person	-το	ἐλύσατο	-ντο	ἐλύσαντο

Verbs that takes a second aorist inflection performs like the irregular verbs  in English and requires some memorization to recognize the commonly used ones.   Once aorist verb stem can be recognized, the verb form can be put together as below: 

Second Aorist	Augment +  Stem + Connecting Vowel + Secondary Active Endings ε + [ stem ] + [ o before μ and ν , and ε elsewhere ] + [secondary active endings]
Example:  λαμβάνω (I take)                γίνομαι (I become)		secondary active endings for singular	Examples	secondary active endings for plural	Examples
Aorist Active Indicative	First person	-ν	ἔλαβον	-μεν	ἐλάβομεν
	Second person	-ς	ἔλαβες	-τε	ἐλάβύετε
	Third person	-ε	ἔλαβυε(ν)	-ν	ἔλάβο(ν)
Aorist Middle Indicable	First person	-μην	ἐγενόμην	-μεθα	ἐγενόμεθα
	Second person	-υ	ἐγένου	-σθε	ἐγένεσθε
	Third person	-το	ἐλένετο	-ντο	ἐγένοντο

Some commonly used second aorist verbs are as below: 

Prsent	Freq	Second aorist	Translation of the aorist	Principal Parts (future active,aorist active, perfect active, perfect middle/passive, aorist passive)
ἀπέρχομαι	117	ἀπῆλθον	I departed	ἀπελεύσομαι, ἀπῆλθον,ἀπελήλυθα, ~, ~
γίνομαι	669	ἐγενόμην	I became, was, happened	γενἠσομαι, ἐγενόμην, γέγονα, γεγένημαι, ἐγενήθην
εἰσέρχομαι	194	εἰσῆλθον	I entered, went in, came in	εἰσελεύσομαι, εἰσῆλθον, εἰσελήλυθα, ~, ~
ἐξέρχομαι	218	ἐξῆλθον	I went out	ἐξελεύσομαι,ἐξῆλθον, ἐξελήλυθα, ~, ~
ἔρχομαι	632	ἧλθον	I came, I went	ἐλεύσομαι, ἦλθον, ἐλήλυθα, ~, ~
ἀποθνῄσκω	111	ἀπέθανον	I died	ἀποθανοὖμαι,ἀπέθανον, ~,~,~
γινώσκω	222	ἔγνων	I knew, I learnt, I realized	γνώσομαι, ἔγνων, ἔγνωκα, ἔγνωσμαι, ἐγνώσθην
εὑρίσκω	176	εὗρον	I found	εὑρήσω, εὗρον, εὕρηκα, ~, εὑρέθην
βάλλω	122	ἔβαλον	I threw, put	βαλῶ, ἔβαλον, βέβληκα, βέβλημαι, ἐβλήθην
ἔχω	708	ἔσχον	I had, kept	ἕξω, ἔσχον, ἔσχηκα, ~, ~
λαμβάνω	258	ἔλαβον	I took, received, seized	λήμψομαι, ἔλαβον, εἴληφα, εἴλημαι, ἐλήμφθην
λέγω	1329	εἶπον	I said, I told, I declared	ἐρῶ, εἶπον, εἴρηκα, εἴρημαι, ἐρρέθην
ὁράω  (cf: βλέπω)	113 (132)	εἶδον (first aorist)	I saw  (I saw, looked at)	ὄψομαι, εἶδον, ἑώρακα/ἑόρακα, ~, ὤφθην (βλέψω, ἔβλεψα, ~, ~, ~)
πίπτω	90	ἔπεσον	I fell	πεσοῦμαι, ἔπεσον, πέπτωκα, ~, ~
ἁμαρτάνω	43	ἡμάρτησα	I sinned	ἁμαρτήσω, ἡμάρτησα, ἡμάρτηκα, ~, ~
ἐσθίω	158	ἔφαγον	I ate	φάγομαι, ἔφαγον, ~, ~, ~
καταλείπω	24	κατέλιπον	I left, abandoned	κατακεἰψω, κατέλιπον, ~, καταλέλειμμαι, κατελείφθην
μανθάνω	25	ἔμαθον	I learnt	~, ἔμαθον, μεμἀθηκα, ~, ~
φέρω	66	ἤνεγκα	I bore, carried, endured	οἴσω, ἤνεγκα, ~, ~, ἠνέχθην
ἄγω	69	ἤγαγον	I led, brought, arrested	ἄξω, ἤγαγον, ~, ~, ἤχθην

Ref: 

Ted Hilebrandt.  Mastering New Testament Greek Textbook.  Chapters 14 and 15 on second and first aorist verbs; as well as Appendix 4 on verb principal parts.  In: Mastering New Testament Greek Textbook.  Downloaded at http://biblicalelearning.org/introductory-languages/mastering-new-testament-greek/.

Andre Van Oudtshoorn.  Bible big ideas new testament greek strong or second aorist.  Perth Bible College Production.  Accessed: https://www.youtube.com/watch?v=wOXtDz6tQXs&feature=youtu.be.