Verbal and Nominal Characteristics
The infinitive is **verbal** (it has tense/aspect and voice; it can take an object and modifiers) and has **nominal syntactic distribution** (it can function as subject, complement, or within an articular phrase). It is **indeclinable**; when an overt subject is independently expressed, it is often in the **accusative**, though many infinitives have a controlled or contextually understood subject.
The infinitive does not independently locate an event in **absolute calendar time**. In many complementary or purpose constructions, the present–aorist contrast is primarily aspectual. In **indirect discourse**, however, infinitival tense can conventionally signal **relative time** with respect to the governing verb: present commonly simultaneous, aorist/perfect anterior, and future subsequent. Interpretation is therefore construction-sensitive.
Present Active Infinitive (λύειν)
The **present active infinitive** has distinct regular formations:
- **thematic verbs**: typically **-ειν**, e.g. **λύειν** ('to loose');
- **athematic (-μι) verbs**: typically **-ναι**, e.g. **εἶναι**, **διδόναι**, **ἱστάναι**.
It normally presents the action with **imperfective viewpoint**, viewing the event from within or without presenting its external boundaries as a whole. An ongoing, durative, iterative, or habitual interpretation may arise from lexeme and context, but is not the invariant meaning of the present infinitive. Do not generalize one ending to all present active infinitives.
**Constructed present-active infinitive:** **λύειν** ('to loose') illustrates the thematic present formation.
**Matt 5:17 — aorist contrast:** **καταλῦσαι** and **πληρῶσαι** are aorist active infinitives, not present infinitives. The verse belongs with the aorist discussion in §36.4.
Present Middle/Passive Infinitive (λύεσθαι)
The **present middle/passive infinitive** ends in **-σθαι**: **λύεσθαι** ('to be loosed' / 'to loose for oneself'). Like the present indicative, middle and passive share the form.
Aorist Active Infinitive (λῦσαι)
The **first-aorist active infinitive** normally accents the **penult**. The accent is circumflex when the penultimate vowel or diphthong is long and the final -αι is short for accentuation, as in **λῦσαι**; a short penultimate vowel takes an acute. Do not generalize 'properispomenon' to every first-aorist active infinitive.
**Thematic second-aorist** active infinitives have **-εῖν**, as in **λιπεῖν**; **root/athematic aorists** include **-ναι** formations such as **γνῶναι**. The aorist infinitive presents perfective viewpoint, not an inherent completed or once-for-all event. Temporal and lexical interpretation depends on construction and context. For negation, see §36.23.
**Matt 5:17** (Patriarchal text; HBS BYZ04) — …οὐκ ἦλθον καταλῦσαι **ἀλλὰ πληρῶσαι** ('I did not come to abolish but **to fulfill**') — πληρῶσαι = aorist active infinitive.
Aorist Middle Infinitive (λύσασθαι)
The **aorist middle infinitive** ends in **-σασθαι**: **λύσασθαι** ('to loose for oneself', perfective viewpoint). Second aorist middle: **γενέσθαι** ('to become', from γίνομαι).
Aorist Passive Infinitive (λυθῆναι)
The **aorist passive infinitive** is illustrated by **λυθῆναι** ('to be loosed'). In the **first passive** formation, the stem extension **-θη-** is followed by infinitival **-ναι**: **λυ- + -θη- + -ναι → λυθῆναι**. The **second passive** formation has **-η-** without θ. These formations must be learned from the verb's own aorist stem; not every passive aorist contains -θη-. The infinitive may occur in purpose, result, and other constructions, whose functions are determined by syntax and context.
Perfect Infinitive (λελυκέναι / λελύσθαι)
The **perfect active infinitive** commonly ends in **-έναι**: **λελυκέναι**. The **perfect middle/passive infinitive** commonly ends in **-σθαι**: **λελύσθαι**. Perfect infinitives are relatively rare. Their semantics must be interpreted according to lexeme, construction, and discourse; they must not be defined universally as encoding a resultant state. In indirect discourse, the perfect infinitive commonly has an **anterior** relative-time interpretation.
Aspect in the Infinitive
The infinitive's tense system must be interpreted **construction-sensitively**.
- **Present infinitive**: typically **imperfective viewpoint**.
- **Aorist infinitive**: typically **perfective viewpoint**.
- **Perfect infinitive**: perfect morphology with semantics determined by lexeme, construction, and discourse.
- **Future infinitive**: especially important in indirect discourse for **prospective/subsequent relative reference**.
In many complementary, purpose, and related infinitival constructions, the present–aorist contrast is primarily aspectual. Properties such as duration, iteration, completion, and telicity are not mechanically read off the form.
In **indirect discourse**, however, infinitival tense can conventionally mark **relative time** with respect to the governing verb: the present commonly represents a simultaneous situation, the aorist and perfect commonly an anterior one, and the future a subsequent one. This relative-time use must not be generalized to every infinitival construction. Thus an aorist purpose infinitive need not denote an action prior to its governing verb.
The contrast between **ποιεῖν** and **ποιῆσαι** in a construction such as 'I want to do' is primarily one of viewpoint, whereas the same tense-forms in indirect discourse may participate in a grammaticalized relative-time contrast.
Complementary Infinitive
A **major use** of the infinitive is to complete the meaning of a finite verb. Verbs of willing, desiring, ability, beginning, and related meanings commonly take infinitival complements: **θέλω ἐλθεῖν**, **δύναμαι σῶσαι**, **βούλομαι ἀγαπᾶν**. The infinitive's subject is often controlled by, or understood from, the governing clause.
**Lexeme note (δέομαι).** In request constructions, **δέομαι** can take a genitive addressee and an infinitival complement. **Constructed illustration:** δέομαι ὑμῶν προσεύχεσθαι, ‘I beg you to pray’. This is a teaching example, not an attributed NT quotation. Distinguish the need/request family, which includes δέω ‘lack/need’, from the homonymous **δέω** ‘bind’. The spelling δέω alone is therefore not a reliable test for selecting the lexical meaning.
**Matt 20:22 — selected excerpt:** …δύνασθε **πιεῖν τὸ ποτήριον** ὃ ἐγὼ μέλλω **πίνειν** … ('…are you able to drink the cup that I am about to drink…'). The excerpt illustrates infinitival complementation; the Patriarchal question continues with the baptism alternative before its question mark.
**Mark 6:48 — selected excerpt:** …ἰδὼν αὐτοὺς **βασανιζομένους** ἐν τῷ **ἐλαύνειν** … ('…seeing them struggling at rowing…').
**Construction distinction:** The Matthew excerpt illustrates infinitival complementation. The Mark excerpt illustrates **ἐν τῷ + articular infinitive**, not a second complementary-infinitive example; compare §§36.18 and 36.20.
Infinitive as Subject
An infinitive can function as the **subject** of a predicate, especially with impersonal expressions: **ἔξεστιν θεραπεύειν** ('it is lawful to heal'), **χρὴ ἀγαπᾶν** ('it is necessary to love'). The infinitive often has a controlled or contextually understood subject. When an overt subject is independently expressed, accusative marking is common, but an explicit accusative subject is not required in every infinitival construction.
**Matt 12:10** (Patriarchal text; HBS BYZ04) — …εἰ **ἔξεστι** τοῖς σάββασι **θεραπεύειν** … ('…whether it is lawful **to heal** on the Sabbath …').
**John 3:14** (Patriarchal text; HBS BYZ04) — …Καθὼς **Μωϋσῆς ὕψωσε τὸν ὄφιν** ἐν τῇ **ἐρήμῳ**, **οὕτως ὑψωθῆναι δεῖ τὸν υἱὸν τοῦ ἀνθρώπου** ('…so must the Son of Man be lifted up') — ὑψωθῆναι is the infinitive subject of impersonal δεῖ.
Infinitive as Object
The infinitive can function as an **infinitival complement** of a verb. In **ἐδίδαξεν αὐτοὺς λέγειν** ('he taught them to speak'), **λέγειν** complements the finite verb, while **αὐτούς** participates in the syntax of the matrix clause and is understood as the subject of the infinitive. The construction should not be reduced mechanically to the statement that the infinitive alone is simply the 'direct object' of teaching.
Epexegetical Infinitive
The **epexegetical infinitive** explains or defines a preceding noun, adjective, or pronoun: **ἡ ἐξουσία τοῦ βαπτίζειν** ('the authority **to baptize**'), **ἱκανός ἐστιν εἰς τὸ λαλεῖν** ('he is competent **to speak**'). It unpacks the content of the preceding word.
Infinitive of Purpose
The infinitive can express **purpose**, especially after verbs of motion or intention: **ἦλθεν ζητῆσαι** ('he came to seek'). Purpose may also be expressed by **εἰς τὸ + infinitive** and, in appropriate contexts, **τοῦ + infinitive**. These forms do **not** mechanically encode purpose: purpose, result, content, or epexegetical relations may overlap, and context must determine the analysis. The aorist infinitive is common in purpose constructions, but its aorist morphology does not itself mean 'prior' or 'completed.'
Purpose inf.: **Matt 2:2** (Patriarchal text; HBS BYZ04) — …**ἤλθομεν προσκυνῆσαι αὐτῷ** ('…we have come **to worship** him') — προσκυνῆσαι = aor. inf., normally read as purpose.
Infinitive of Result
The infinitive can express **result or consequence**, especially with **ὥστε + infinitive**. The construction commonly presents an actual, expected, intended, or contemplated consequence depending on context. An intended or contemplated result may approach purposive meaning pragmatically, but **ὥστε + infinitive** should not be treated as a simple grammatical synonym of a purpose construction. Where the contextual analysis is genuinely uncertain, mark it explicitly as disputed.
Infinitive in Indirect Discourse
After verbs of **saying, thinking, and perceiving**, infinitival and participial complement constructions can report or represent content. The classical **accusative + infinitive** pattern is much reduced in New Testament Koine, where **ὅτι + finite verb** is common. With perception verbs, participial complements are important, but they are not the only available pattern; finite clauses and other complementation strategies also occur. In indirect discourse, infinitival tense can carry relative-time relations to the governing verb.
Articular Infinitive
The infinitive can take the neuter singular article and form an **articular infinitive**: **τὸ ζῆν**, **ἐν τῷ βαπτίζεσθαι**. The infinitive itself remains **indeclinable**; the **article** bears case marking, and any governing preposition determines the case of the article. The construction can function in nominal, temporal, causal, purposive, and other relations according to preposition and context. Nominal use does not remove verbal properties: the infinitive retains tense-form and voice and can take the complements licensed by its verb.
**Phil 1:21** (Patriarchal text; HBS BYZ04) — Ἐμοὶ γὰρ τὸ **ζῆν Χριστὸς** καὶ τὸ **ἀποθανεῖν κέρδος** ('For to me, **to live [is] Christ**, and **to die [is] gain**') — articular infinitives as subjects.
Genitive Articular Infinitive
**τοῦ + infinitive** can express several relations, including **purpose**, **result**, **content/epexegesis**, and other context-dependent functions. It therefore must not be assigned a single mechanical meaning. Where purpose and content/epexegesis are both defensible, GOLD should classify the analysis as ambiguous rather than forcing a single label. Illustrations should describe the syntactic relation directly and avoid turning a genitive relation into an unsupported claim about verbal voice or agency.
Dative Articular Infinitive
The especially common construction **ἐν τῷ + infinitive** is often **temporal**, expressing circumstances such as 'when' or 'while': **ἐν τῷ βαπτίζεσθαι αὐτόν** ('when/while he was being baptized'). The temporal value belongs to the construction as a whole, especially the preposition **ἐν** with the dative articular infinitive; bare **τῷ + infinitive** should not be assigned one universal temporal meaning.
Accusative Articular Infinitive
The neuter singular article **τὸ** has the same surface form in the nominative and accusative. With an articular infinitive, case must therefore be determined by syntax. In **τὸ ζῆν Χριστός** (Phil 1:21), the subject phrase is nominative. An object use or a preposition governing the accusative can license an accusative articular infinitive. The infinitive itself remains indeclinable.
Articular Infinitive with Prepositions
Prepositions can govern the articular infinitive. The **article** bears the case required by the preposition; the infinitive itself remains indeclinable. Function depends on the preposition plus context:
- **εἰς τὸ + infinitive** — often purpose or result.
- **ἐν τῷ + infinitive** — commonly temporal ('when/while').
- **διὰ τὸ + infinitive** — commonly causal.
- **μετὰ τὸ + infinitive** — temporal, commonly locating the infinitival event before the matrix event ('after doing …').
- **πρὸ τοῦ + infinitive** — temporal, locating the matrix event before the infinitival event ('before doing …').
These are constructional tendencies, not meanings supplied by case alone.
Subject of the Infinitive
The subject of an infinitive may be **controlled or understood from context**, especially when it is coreferential with an argument of the governing verb. When an overt, independently expressed infinitival subject is present, the **accusative** is an important and common pattern: **ἐκέλευσεν αὐτοὺς ἀπελθεῖν** ('he ordered them to leave'). Accusative marking is therefore significant, but it is not a universal 'hallmark' required by every infinitive construction.
Accusative Subject of the Infinitive
The **accusative subject + infinitive** construction is a major Classical Greek pattern for indirect statement, but it is much reduced in New Testament Koine, where **ὅτι + finite verb** is common. A constructed pedagogical illustration is **νομίζω Ἰησοῦν εἶναι τὸν Χριστόν** ('I think that Jesus is the Christ'); this is an illustration of the syntax, not a quotation from the New Testament. Actual NT examples should be identified separately and tied to their textual source.
A genuine NT accusative + infinitive of indirect statement is relatively uncommon; most NT 'they said that …' uses ὅτι + finite verb (Chapter 62).
Negation of the Infinitive
**μή** is the normal negative with many infinitival constructions: e.g. **μὴ ἀποθανεῖν** ('not to die'). The distribution is nevertheless **syntactically conditioned**, not an absolute rule that excludes **οὐ** from every infinitival environment. In indirect assertion and related constructions, οὐ may occur where the infinitive represents or preserves the negation of the reported proposition. In **Matt 5:17**, **οὐκ** negates the finite verb **ἦλθον**, not the infinitive **καταλῦσαι**.
Decline of the Infinitive in Later Greek
The infinitive was robust in Classical Greek but was **declining in Koine**, with finite subordinate constructions—especially **ἵνα + subjunctive** in many environments—expanding at its expense. This is a **diachronic tendency**, not evidence that infinitival complementation had disappeared from New Testament Greek. The change is multifactorial and shows register and constructional variation.
Paradigms
Infinitive Endings by Tense and Voice (λύω)
Infinitival tense/aspect is construction-sensitive. Present and aorist commonly contrast imperfective and perfective viewpoint, while perfect morphology must not be reduced to a universal result-state meaning. In indirect discourse, infinitival tense can also express relative time: present commonly simultaneous, aorist/perfect anterior, and future subsequent. Present middle/passive **λύεσθαι** and perfect middle/passive **λελύσθαι** are morphologically syncretic; voice interpretation depends on lexeme and context.
| Tense | Active | Middle | Passive |
| Present | λύειν to loose | λύεσθαι | λύεσθαι |
|---|---|---|---|
| Future | λύσειν | λύσεσθαι | λυθήσεσθαι |
| Aorist | λῦσαι | λύσασθαι | λυθῆναι |
| Perfect | λελυκέναι | λελύσθαι | λελύσθαι |
Chapter glossary
- λύειν — to loose (present)
lyein
verb
Present active infinitive; imperfective viewpoint (ongoing realization is contextual, not definitional).- λῦσαι — to loose (aorist)
lysai
verb
Aorist active infinitive; perfective viewpoint; circumflex on penult (properispomenon).- λυθῆναι — to be loosed (aorist passive)
lythēnai
verb
λυθῆναι is the aorist passive infinitive of λύω: λυ- + -θη- + -ναι → λυθῆναι, 'to be loosed'. The circumflex stands on the penultimate syllable -θῆ-.- λελυκέναι — to have loosed (perfect)
lelykenai
verb
Perfect active infinitive; -έναι ending. Perfect morphology must be interpreted according to lexeme, construction, and discourse and is not universally reducible to a resultant-state meaning.- δέομαι — to beg / request / need
deomai
verb
δέομαι has middle-form present morphology and means ‘need’, ‘ask’ or ‘beg’ according to its construction. It can take a genitive person and an infinitive in a request. Its paradigm includes future δεήσομαι and passive-form aorist ἐδεήθην; traditional deponent terminology must not obscure those forms. It belongs to the need/request family associated with δέω ‘lack/need’, distinct from the homonymous δέω ‘bind’.- — infinitive
verb
A non-finite verbal form with verbal properties and nominal syntactic distribution. Its present–aorist contrast is primarily aspectual in many constructions, while in indirect discourse infinitival tense can also express relative time; it does not independently encode absolute calendar time.- — complementary infinitive
syntax
Infinitive completing a finite verb: θέλω ἐλθεῖν 'I want to come'.- — articular infinitive
syntax
An infinitive with the neuter singular article, used nominally while retaining verbal properties such as tense-form, voice and the ability to take complements. The article marks case; the infinitive remains indeclinable. Example: τὸ ζῆν, 'living / to live'.- — epexegetical infinitive
syntax
Infinitive explaining/defining a preceding word: ἡ ἐξουσία τοῦ βαπτίζειν 'the authority to baptize'.- — infinitive of purpose
syntax
Infinitive expressing 'in order to': ἦλθεν ζητῆσαι 'he came to seek'.- — purpose/result (ambiguous)
syntax
DISPUTED ANALYSIS: a bare or articular infinitive (esp. τοῦ/εἰς τὸ + inf.) that can be read as either purpose or result; classify as ambiguous where context does not decide.- — accusative + infinitive
syntax
A construction in which an overt infinitival subject may appear in the accusative; important in Classical indirect statement but reduced in the NT, where ὅτι + finite verb is common. Many infinitives instead have controlled or contextually understood subjects.