Infinitive Uses

Verbal Aspect
Uses of the Infinitive
1. Accusative Subject
2. Negation
Subjective Infinitive
1. Dative of Reference
Complementary Infinitive
Articular Infinitive

Verbal Aspect

Before we discuss how we can use an infinitive in a sentence, we have to nuance one feature of the verb that we’ve learned about so far: tense. In a finite verb, tense indicates when the action of the verb happens in an absolute sense (meaning in terms of “real time”). The present tense indicates that a verb’s action is happening now, while the aorist tense indicates that a verb’s action is a completed one-and-done event of the past.

In non-finite verb forms like infinitives and particples, however, the tense of the verb form means something slightly different. In infinitives and participles, tense indicates the aspect of a verb, a quality of the verb that indicates its duration and/or its state of completeness.

Verb forms built on the 1st principal part have present aspect, which means that the verbal action takes place over a period of time and/or is incomplete/in progress.

Verb forms built on the 3rd and 6th principal parts have aorist(ic) aspect, which means that the verbal action is instantaneous and/or is completed/done.

Aspect can also indicate a verbal action’s relative time in comparison to the action of the main verb of a sentence. Present aspect can indicate that the verb form’s action is happening at the same time as the main verb’s action; aoristic aspect can indicate that the verb form’s action happened before the main verb’s action. Note how this differs from the absolute time of a finite verb form; while a form like ποιεῖ (3rd sg. pres. act. ind.) indicates that an action is happening right now, an infinitive like ποιεῖν might indicate that the action of doing or making is happening at the same time as the action of a main verb, which itself can be in the past or the future.

Uses of the Infinitive

Infinitives are verbal nouns that can fulfill functions that regular nouns do. Unlike regular nouns, infinitives do not get declined. However, like nouns, they have a gender and a number (neuter singular), they have a case that corresponds to a function within a sentence, and they can be used with appropriate forms of the definite article, especially when they serve as objects of prepositions or are in the genitive or dative cases.

We must keep in mind that infinitives are almost always used in the context of a main verb; an infinitive cannot be the main verb of a sentence. If you spot an infinitive, it will most likely be governed by the conjugated verb in the sentence or by a preposition that links it to the conjugated verb.

Accusative Subject

In all of the following uses of the infinitive, the actor of the infinitive’s action (if active or middle) or the entity receiving the verb’s action (if passive) goes into the accusative case and is called a subject accusative or accusative subject. Sometimes, it makes sense to translate such a subject with the preposition “for”, as we’ll see in the coming examples.

This use of the accusative can be confusing, since an accusative noun can also still indicate that it’s a direct object of the infinitive. Context will help you determine which of the uses of the accusative, direct object or subject accusative, is appropriate for each noun.

Negation

If you want to negate any of the following uses of the infinitive, the negation is μή, as opposed to οὐ (οὐκ, οὐχ). While οὐ is used to negate most finite, indicative verb forms, μή is used outside of those contexts, as here for infinitives.

Subjective Infinitive

A subjective infinitive, as the name implies, serves as the subject of a sentence. Most often, the main verb of such sentences that would take a subject infinitive is an impersonal verb, one that in English uses a dummy subject “it” and is most often 3rd person singular. Note the examples in the Week 12 Vocabulary: δεῖ and χρή, which both mean “it is necessary”; πρέπει, “it is fitting”; and ἔξεστι(ν), a form of εἰμί with the prefix ἐξ, “it is possible;” δοκεῖ (> δοκέω), “it seems best.” You can also use the neuter singular of an adjective in predicative position to fulfill the same role as an impersonal verb. For example, δίκαιον, “it is just”, or ἄδικον, “it is unjust.”

Here are some examples and explanations.

δεῖ τὸν μαθητὴν τούσδε τοὺς λόγους ἀκούειν.
- It is necessary for the student to hear these words.

The infinitive ἀκούειν is a subjective infinitive used with the impersonal verb δεῖ. At its core, the idea of the sentence is “it is necessary to hear” – τὸν μαθητὴν and τούσδε τοὺς λόγους just add additional information. Another way to rewrite the core of the sentence to make it clear that the infinitive is subjective would be “to hear is necessary” or “hearing is necessary.”

In this example, we have two accusatives: τὸν μαθητὴν and τούσδε τούς λόγους. So, we need to make a decision about which serves as the accusative subject and which serves as the accusative direct object of ἀκούειν. Here, context and definitions can help. τὸν μαθητὴν means “the student”, which is a person, while τούσδε τούς λόγους means “these words”, which are things. When it comes to the action of “hearing” in the active infinitive ἀκούειν, it does not make sense for words to perform that action upon a student (“It is necessary for these words to hear the student”); so, it must be the other way around, with τὸν μαθητὴν as the accusative subject and τούσδε τούς λόγους as the accusative direct object.

The addition of the accusative subject τὸν μαθητὴν and the direct object τούσδε τοὺς λόγους help fill out the picture of what it is necessary to hear and who it’s necessary for; they take advantage of the verbal part of the infinitive. As a result, in translation, we can turn a subjective infinitive phrase that contains an accusative subject and other predicate features like direct objects or prepositional phrases into their own dependent clauses beginning with the linking word “that”. We can rewrite the translation above in the following way: “It is necessary that the student hear these words”.

The whole infinitive unit (τὸν μαθητὴν τούσδε τοὺς λόγους ἀκούειν) functionally serves as the subject of δεῖ. What is necessary? The idea that the student hear these words.

Keep in mind that as mentioned above, if you want to negate the infinitive, you should use the negation μή: δεῖ τὸν μαθητὴν τούσδε τοὺς λόγους μὴ ἀκούειν, “It is necessary that the student not near these words.”

χρὴ τὰ ἔργα ποιεῖσθαι.

This sentence is comprised of three main units: the main verb χρή, the accusative τὰ ἔργα, and the present middle/passive infinitive ποιεῖσθαι. Because there are different possibilities for the latter two parts (i.e., the accusative can either be a direct object or an accusative subject, and the infinitive can be either middle or passive), there are a few different possibilities for translation.

If we assume that τὰ ἔργα is a direct object and that ποιεῖσθαι is middle: “It is necessary to do the deeds.” In this case, we wouldn’t get an explicit subject for the infinitive.
If we assume that τὰ ἔργα is an accusative subject and that ποιεῖσθαι is passive: “It is necessary that the deeds be done.”

Dative of Reference

Often, a substantive in the dative case can be used to indicate to whom a statement applies. This is a use of the dative called the dative of reference, and it often appears in sentences with a subjective infinitive and an impersonal verb. Take a look at the following examples:

ἄδικον τοῖς πολῖταις τὸ πρᾶγμα.
- The deed is unjust to/for the citizens.
δοκεῖ τῷ ἀγαθῷ εἰς τὴν οἰκίαν ἔρχεσθαι.
- It seems best to/for the noble person to come into the house.

Complementary Infinitive

An infinitive can also complete the action of a verb in a predicative fashion, rather than the subjective fashion discussed above. Complementary infinitives function as objects rather than subjects in their sentences, and the verbs that necessitate complementary infinitives tend to be more active and transitive than the impersonal verbs discussed above. For example, note ἐθέλω, “to want”, and the deponent -μι verb δύναμαι, “to be able to, can”, in the Week 12 Vocabulary above. Also, verbs of commanding like κελεύω, “to order”, can take a complementary infinitive as well (in addition usually to an accusative subject).

Note the following examples:

οἱ πολῖται ἐθέλουσιν αἱρεῖν τὰ ὅπλα.
- The citizens wish to take the weapons.

In this sentence, the action of taking in αἱρεῖν indicates what the citizens want; it serves as the object. Because it is a verbal form itself, it also takes its own direct object: τὰ ὅπλα. Note that when the subject of the main verb and the subject of the infinitive match, you do not need to repeat it; the citizens will be the ones taking the weapons in this sentence.

You can, however, introduce an accusative subject if the actor of the infinitive is not the same as the actor of the main verb:

οἱ πολῖται ἐθέλουσι τοὺς δικαστὰς αἱρεῖν τὰ ὅπλα.
- The citizens want the jurors to take the weapons.

We need to use the same reasoning explained above to figure out which of our two accusatives (τοὺς δικαστὰς and τὰ ὅπλα) serves as the subject of αἱρεῖν and which serves as its direct object. Again, we have a difference between people and things, and when it comes to performing the action of an active infinitive, it makes the most sense to take τοὺς δικαστὰς as the accusative subject and τὰ ὅπλα as the direct object of the infinitive, rather than the other way around (“The citizens want the weapons to take the jurors” doesn’t make sense!).

In the following example, note the combination of an accusative subject with the infinitive:

ὁ διδάσκαλος κελεύει τοὺς μαθητὰς ἀγαθὰ λέγειν.
- The teacher orders the students to say good things.

The infinitive λέγειν serves as the complement, the object, of the main verb κελεύει. What does the teacher order? The action of speaking (λέγειν). The infinitive takes an accusative subject τοὺς μαθητὰς (masc. acc. pl.) and an accusative direct object ἀγαθὰ (neut. acc. pl.). As in the previous example, while it is technically possible to swap the uses of each substantive since they are both in the accusative case, it wouldn’t make much sense logically given what the substantives mean: “The teacher orders the good things to say the students.” Thus, you can use context like the definitions of your substantives to reason out what belongs where.

Articular Infinitive

In both of these contexts (subjective infinitive, complementary infinitive) and in others, like when the infinitive serves as the object of a preposition or when it’s used in the genitive or dative case, the infinitive can take the definite article in an appropriate gender (neuter), number (singular), and case.

So, note the examples from above rewritten with an article:

χρὴ τὸ τὰ ἔργα ποιεῖσθαι. (subjective)
- It is necessary to do the deeds.
ὁ διδάσκαλος κελεύει τὸ τοὺς μαθητὰς ἀγαθὰ λέγειν. (complementary)
- The teacher orders the students to say good things.

Note that the article and the infinitive are like any article-noun pair; the article matches the infinitive in gender, case, and number, and anything that serves to modify or give context to the infinitive/noun can be placed in attributive position. This includes any accusative subjects, accusative direct objects, prepositional phrases, or adverbs like the negation μή. Note that these can also be placed in predicative position: χρὴ τὸ ποιεῖσθαι τὰ ἔργα / ὁ διδάσκαλος κελεύει τοὺς μαθητὰς ἀγαθὰ τὸ λέγειν.

An article must be used with an infinitive that is an object of a preposition and/or in the genitive or dative case. In these cases, a “[verb]ing” translation might make the most sense for the infinitive in question, or if the infinitive gets an accusative subject, you might turn it into its own dependent clause, based on what the preposition means. For example:

ἐκ τοῦ τὴν γυναῖκα τὸν οἶνον μειγνύναι, οἱ πολῖται κακὰ ἐποίησαν.
- As a result of (from) the woman mixing the wine, the citizens did bad things.

τοῦ … μειγνύναι serves as the object of the preposition ἐκ, and since ἐκ takes the genitive case, that is the case that the articular infinitive goes into, as indicated by the article. We can use the same reasoning that we used above to figure out the uses of τὴν γυναῖκα and τὸν οἶνον as, respectively, accusative subject and accusative direct object. The prepositional phrase here serves an adverbial function; it explains the reason why the citizens were doing bad things (namely because of the act of mixing). So if we break free of “literal” translation, we can communicate the same idea in other ways, like with its own dependent clause that starts off with a conjunction; for example: “Because the woman mixed the wine, he was doing bad things.”

πρὸς τὸ τὰ ὅπλα ἑλεῖν, οἱ ἄνδρες καὶ τοὺς ἵππους ἤγαγον.
- In addition to taking the weapons, the men also led the horses.

The preposition here serves as a bridge word that connects the action of taking (ἑλεῖν) to the action of leading; here, “taking” happens in addition to leading.

In sum, the infinitive acts as a verbal unit that can take its own subjects, objects, prepositional phrases, and adverbs, but it is almost always used in the context of a main, conjugated, finite verb. The infinitive relates to the main verb in some way: it can serve as its subject (subjective infinitive), as its object (complementary infinitive), or as an adverbial modifier via a connecting preposition (prepositional object).