User:Robert.Baruch/Latin Infinitives

About Latin infinitives.

Nouns
Latin infinitives can be used as nouns!

As nominatives
As nominatives, infinitives are always neuter. So we can say:
 * To err is human.
 * Errare est humanum. (Or as we see it more often, Errare humanum est).

In English, we have gerunds. If they can be converted to infinitives, then they are translated as infinitives (but see below):
 * Fighting is dying. => To fight is to die.
 * Pugnare mori est.

As accusatives (objects of verbs)
Infinitives can also be objects of verbs, and again they are neuter. So we can say:
 * I tried to speak, but I had no mouth.
 * Conatus sum dicere, sed non erat mihi os.

One common phrase is Necesse est mihi (It is necessary for me...) and it takes an object infinitive:
 * I must (It is necessary for me to) speak, but I have no mouth.
 * Necesse est mihi dicere, sed non est mihi os.

NEVER as accusatives (of prepositions)
If we said something like:
 * Beyond fighting, I like sleeping. => Beyond to fight, I like to sleep.

It sounds a bit strange. Since infinitives cannot be objects of prepositions, we cannot say:
 * (*) Super pugnare, diligo dormire.

Instead, we must use a gerund:
 * Super pugnandum, diligo dormire.

NEVER as genitive, dative, or ablative
Yes as nominatives, and mostly as accusatives, but never as the other cases. Instead, use a gerund.

NEVER as purpose clause
NEVER! In English, we say things like, "I went to the store to buy an apple." That's a purpose clause, and there are a few ways to translate purpose clauses into Latin. But the infinitive is not it. Instead, mentally insert "in order to", and thus use ut + subjunctive.

Tenses: present, perfect, future
The present is one of the principal parts of the verb.
 * Present: dormire (to sleep)

To form the perfect tense, take the perfect tense of the verb and add -sse. If the result ends in -ivisse, then typically it is shortened to -isse.
 * Perfect: dormivisse or dormisse (to have slept)

To form the future tense, take the perfect passive participle of the verb and replace -um with -urum.
 * Future: dormiturum esse (to be about to sleep)

The tenses are used relative to the tense of the main verb. So we have:
 * I like sleeping => I like to sleep.
 * Diligo dormire.


 * I liked sleeping => I liked to sleep.
 * Dilexi dormire.


 * I will like sleeping => I will like to sleep.
 * Diligam dorimire.

But:
 * I like to be about to sleep. (Presumably I like that drowsy feeling preceding sleep.)
 * Diligo dormiturum esse.

Passive
The present passive is formed from the present:
 * Present passive: necari (to be murdered)

The perfect is formed from the perfect passive participle, with esse (the infinitive of sum)
 * Perfect passive: necatum esse (to have been murdered)

The future is formed from the perfect passive participle, with iri (the future infinitive of sum)
 * Future passive: necatum iri (to be about to be murdered)