Historical Grammar
546. The second aorist is formed without any tense-suffix and only from the simple verb-stem. Only primitive verbs (372) have second aorists.
547. (I) Ω-Verbs. – Ω-verbs make the second aorist by adding ο/ε- to the verb-stem, which regularly ends in a consonant. Verbs showing vowel gradations (476) use the weak stem (otherwise there would be confusion with the imperfect).
λείπω (λιπ-, λειπ-) leave ἔλιπον, -ἐλιπόμην; φεύγω (φυγ-, φευγ-) flee ἔφυγον; πέτομαι fly ἐπτόμην (476 a); λαμβάνω (λαβ-) take ἔλαβον.
548. a. Vowel verbs rarely form second aorists, as the irregular αἰρέω seize (εἶλον, 529. 1), ἐσθίω eat (ἔφαγον), ὁράω (εἶδον). ἔπιον drank (πί̄νω) is the only second aorist in prose from a vowel stem and having thematic inflection.
b. Many ω-verbs with stems ending in a vowel have second aorists formed like those of μι-verbs. These are enumerated in 687.
549. Verbs of the First Class (499) adding a thematic vowel to the verbstem form the second aorist (1) by reduplication (494), as ἄγω lead ἤγαγον, and εἶπον probably for ἐ-Ϝε-Ϝεπ-ον; (2) by syncope (493), as πέτομαι fly ἐπτόμην, ἐγείρω (ἐγερ-) rouse ἠγρόμην, ἕπομαι (σεπ-) follow ἐσπόμην, imperf. είπόμην from ἐ-σεπομην, ἔχω (σεχ-) hare ἔσχον; (3) by using α for ε (476 b) in poetic forms (480), as τρέπω turn ἔτραπον; (4) by metathesis (492), as poet. δέρκομαι see ἔδρακον.
550. (II) Μι-Verbs. – The stem of the second aorist of μι-verbs is the verb-stem without any thematic vowel. In the indicative active the strong form of the stem, which ends in a vowel, is regularly employed. The middle uses the weak stem form.
ἵ-στη-μι (στα-, στη-) set, second aorist ἔστην, ἔστης, ἔστη, ἔστητον, ἐστήτην, ἔστημεν, ἔστητε, ἔστησαν; middle ἐ-θέ-μην from τίθημι (θε-, θη-) place, ἐ-δό-μην from δίδωμι (δο-, δω-) give.
551. Originally only the dual and plural showed the weak forms, which are retained in the second aorists of τίθημι, δίδωμι, and ἵ̄ημι: ἔθεμεν, ἔδομεν, εἷμεν (ἐ-έμεν), and in Hom. βάτην (also βήτην) from ἔβην went. Elsewhere the weak grades have been displaced by the strong grades, which forced their way in from the singular. Thus, ἔγνον, ἔφῠν in Pindar (= ἔγνω-σαν, ἔφῡ-σαν), which come from ἐγνων(τ), ἐφῡν(τ) by 40. So Hom. ἔτλᾰν, ἔβᾰν. Such 3 pl. forms are rare in the dramatic poets.
a. For the singular of τίθημι, δίδωμι, ἵ̄ημι, see 755; for the imperatives, 759; for the infinitives, 760.
552. No verb in -ῡμι has a second aorist in Attic from the stem in υ.
Syntax & Usage
1923. The aorist expresses the mere occurrence of an action in the past. The action is regarded as an event or single fact without reference to the length of time it occupied.
ἐνίκησαν οἱ Κερκυραῖοι καὶ ναῦς πέντε καὶ δέκα διέφθειραν the Corcyraeans were victorious and destroyed fifteen ships T. 1. 29, Παιώνιος ἐποίησε Paeonius fecit I. G. A. 348, ἔδοξεν τῇ βουλῇ it was voted by (seemed good to) the Senate C. I. A. 1. 32.
a. The uses of the aorist may be explained by the figure of a point in time: 1. The starting point (ingressive aorist, 1924); 2. The end point (resultative aorist, 1926); 3. The whole action (beginning to end) concentrated to a point (complexive aorist, 1927).
1924. Ingressive Aorist. — The aorist of verbs whose present denotes a state or a continued action, expresses the entrance into that state or the beginning of that action.
a. This holds true of the other moods. Greek has no special form to denote entrance into a state in present time (1853).
Loquentes Practice Reference
Our drill practices λαμβάνω / ἔλαβον. Smyth § 547 forms the second aorist exactly this way and names both models: λείπω (λιπ-, λειπ-) leave ἔλιπον, -ἐλιπόμην and λαμβάνω (λαβ-) take ἔλαβον. § 550 gives the corresponding rule for μι-verbs.
Source note: §§ 546–552 state the formation and give the principal parts as prose; Smyth's inflected second-aorist paradigm of λείπω sits on p. 119 (§§ 383–384), which the CCEL snapshot does not contain. This lesson therefore carries no paradigm table rather than substituting an unrelated one.