LESSON XLIX: The Infinitive

Formation of the Infinitive

453. The tenses occurring in the infinitive are the present, future, aorist, perfect, and future perfect. The middle and passive differ from one another, in form, only in the future and aorist.

454. Learn the eleven forms of the infinitive active, middle, and passive of λύω.

Infinitive of λύω
Present Activeλύειν
Present Middle and Passiveλύε-σθαι
Future Activeλύσειν
Future Middleλύσε-σθαι
Future Passiveλυθήσε-σθαι
Aorist Activeλῦσαι
Aorist Middleλύσα-σθαι
Aorist Passiveλυθῆ-ναι
Perfect Activeλελυκέ-ναι
Perfect Middle and Passiveλελύ-σθαι
Future Perfect Middle and Passiveλελύσε-σθαι

The Formation of the Infinitive

455. The endings are in the active εν and ναι; in the middle and passive σθαι.

456. The ending εν contracts with a preceding ε to ειν (λῡε-εν, λύειν). The perfect active and aorist passive add ανι, but the perfect changes α of the stem to ε (λελυκα, λελυκέ-ναι), and the aorist lengthens the tense suffix as in the indicative (λυθε, λυθῆ-ναι). The aorist active (λῦσαι) is irregular in form.

457. The accent of verbs is recessive (53), but all infinitives in ναι (as λελυκέναι, λυθῆναι), the aorist active infinitive (λῦσαι, βουλεῦσαι), and the perfect middle and passive infinitive (λελύσθαι) accent the penult.

The Present Infinitive of εἰμί

458. The present infinitive of εἰμί is εἶναι (795).

The Present Infinitive of Contract Verbs

459. Learn the present infinitive active, middle, and passive of τῑμάω, ποιέω, and δηλόω.

Present Active Infinitive of τῑμάω(τῑμάειν) τῑμᾶν
Middle and Passive Infinitive of τῑμάω(τῑμάεσθαι) τῑμᾶσιθαι
Present Active Infinitive of ποιέω(ποιέειν) ποιεῖν
Present Middle and Passive Infinitive of ποιέω(ποιέεσθαι) ποιεῖσθαι
Present Active Infinitive of δηλόω(δηλόειν) δηλοῦν
Present Middle and Passive Infinitive of δηλόω(δηλόεσθαι) δηλοῦσθαι

The Formation of the Present Infinitive of Contract Verbs

460. Observe that

(1)α + ει or ε = ᾱ;
(2)ε + ει or ε = ει;
(3)ο + ει or ε = ου.

The Uses of the Infinitive

461. Many of the uses of the infinitive are identical in Greek and English. E.g.:

1. Κῦρος κελεύει τὸν στρατηγὸν ἡγεῖσθαι, Cyrus commands the general to lead.

2. βουλόμεθα ἀποχωρεῖν, we wish to withdraw.

3. συνεβούλευον τοῖς στρατιώταις μὴ ταῦτα ποιῆσαι, I advised the soldiers not to do this.

4. ἀδύνατόν ἐστι ταῦτα ποιῆσαι, it is impossible to do this.

5. δεῖ τοὺς λοχᾱγοὺς σπεύδειν, the captains must make haste:

6. οὗτοι ἱκανοὶ ἦσαν τὰς κώμᾱς φυλάττειν, these were sufficient to guard the village.

7. τὴν χώρᾱν ἐπέτρεψε διαρπάσαι τοῖς Ἕλλησι, he turned the country over to the Greeks to plunder.

Thus, the subject of the infinitive is in the accusative (cf. 1, 5), but it is generally omitted if it is the same as the subject or the object (direct or indirect) of the leading verb (cf. 2, 3, 6, 7).

The infinitive may be the subject nominative of a finite verb, especially of an impersonal verb or ἐστί (cf. 4, 5).

The infinitive may be the object of a verb whose action naturally implies another action as its object especially of verbs expressing wish, command, advice, attempt, and the like (cf. 1, 2, 3).

The infinitive may depend on adjectives, especially those expressing ability, fitness, willingness, and the like (cf. 6). Finally, it may express purpose (cf. 7). The negative with the infinitive in these cases is μή (cf. 3).


ἀδύνατος, ονunable, impossible.
ἀμφότερος, ᾱ, ονboth.
ἀνάγκη, ης, ἡforce, necessity.
ἀφ-ικνέομαι (ἱκ), ἀφ-ίξομαι, ἀφ-ῑκόμην, ἀφ-ῖγμαιcome from, arrive, reach.
δια-σῴζωbring through safely, save.
ἐπι-τρέπωturn over to, entrust, allow.
λόχος, ου, ὁ(cf. λοχ-ᾶγός)company.
τρέπω, τρέψω, ἔτρεψα and ἔτραπον, τέτροφα, τέτραμμαι, ἐτράπην and ἐτρέφθηνturn, direct, rout.
φυγή, ῆς, ἡ (cf. φεύγω)flight, rout.


1. τὰ γὰρ ἐπιτήδεια οὐκ ἔστιν ἔχειν.
2. ἥκομεν γὰρ ὑμᾶς σῴζειν.
3. ἀλλ᾿ οὔπω ἀνάγκη ἐστὶ φεύγειν.
4. ἀδύνατον ἔσται τῆς νυκτὸς ἀφικνεῖσθαι.
5. ἀμφοτέροις παρεκελευσάμεθα τῆς ὀργῆς1 παύσασθαι.
6. αὐτοῖς ἐπέτρεψε τοὺς παῖδας διδάσκειν.
7. ἡμεῖς χρῄζομεν διασωθῆναι πρὸς τὴν Ἑλλάδα.
8. τῶν ὁπλῑτῶν δύο λόχους ἐκέλευσε ἕπεσθαι αὐτῷ.
9. πολεμεῖν ἱκανοὶ ἦσαν καὶ εὐνοϊκῶς εἶχον Κύρῳ.
10. ἐβόων ἀλλήλοις τοὺς καθ᾿ ἑαυτοὺς πολεμίους εἰς φυγὴν τρέψαι.

NOTE.—1 A genitive of separation. cf. 336, 1.

465. Proxenus interferes, and Cyrus comes riding up.

ὁ δὲ Πρόξενος — ὕστερος γὰρ προσήλαυνε καὶ λόχος αὐτῷ εἵπετο τῶν ὁπλῑτῶν — εὐθὺς οὖν εἰς τὸ μέσον ἀμφοτέρων ἄγων ἐδεῖτο τοῦ Κλεάρχου μὴ ποιεῖν ταῦτα. ὁ δὲ χαλεπαίνει ὅτι πρᾴως λέγει τὸ αὑτοῦ πάθος, ἐκέλευσέ τε αὐτὸν ἐκ τοῦ μέσου ἰέναι. ἐν τούτῳ δὲ ἀφικνεῖται καὶ Κῦρος καὶ ἀκούει τὸ πρᾶγμα. εὐθὺς δ᾿ ἔλαβε τὰ παλτὰ εἰς τὰς χεῖρας καὶ μετὰ τῶν πιστῶν ἧκεν ἐλαύνων εἰς τὸ μέσον, καὶ λέγει τάδε.

NOTES.— 2. οὖν: the narrative has been interrupted and is resumed with οὖν.— 3. ἐδεῖτο τοῦ Κλέαρχου κτλ.: besought Clearchus not to do this. — 4. ὅτι πρᾴως λέγει κτλ.: because he spoke lightly of his trouble.— 5. ἰέναι: to go, to get, present infinitive of εἶμι, go.