Formation of the Supine
It’s a rare bit of grammar, but we’re lucky, because it’s simple. It takes one of only four forms:
- The supine is always a fourth-declension (the -us, -ūs declension) noun, and always appears in the accusative or ablative
- Moreover, these forms will always have an initial t- or s-, leaving four possible endings: -tum, -sum, -tū, and -sū
The accusatives move with verbs; the ablatives move with adjectives: vēnit spectātum [he came to see]; mirabile dictū [marvelous to tell]
You have the endings, now consider the stems:
- The supine stem is always identical to the perfect passive participle’s stem
- amātus: amātum, amātū; rectus: rectum, rectū
Uses of the Supine
As I mentioned just above, there are four forms with two endings, and therefore two uses:
The supine accusatives, -tum and -sum are “used after verbs of motion to express purpose” (AG, 509)
- nam vēnī dē tumultū te admonitum, quem cum abīrēs linquistī: and I’m here to remind you, of the mess you left when you ran away
- pārentēs abībit inventum postrīdiē: she leaves tomorrow to find her parents
Not that the supine is a singular accusative, even where it follow a plural verb, or takes a plural object
The supine ablatives, -tū and –sū are used with a handful of adjectives, as a means of reference
- iste senex foedus et visū et olfactū est: that geezer is hard on the eyes and the nose
- nulla optima via catō deglūbū est: there is no best way to skin a cat
The ablatives may also appears with fās, nefās and opus, again as a means of reference
- this is unholy to say: hōc nefās dictū est
- this letter is a burden to write: literra opus scriptū est.
The supine ablatives are commonly attached to statements about the senses, or statement denoting easy or difficulty.
Essential AG: 94.b; 509-10
Latin for Addicts 