ARE: Lesson - The Irregular Verb posse
The Irregular Verb posse
In the previous section, a particular verb was mentioned as one that requires an infinitive to complete its meaning. This was the irregular verb possum, posse, potui - to be able. This irregular verb is a compound of the adjective potis (an indeclinable adjective meaning able, capable, possible) with the forms of sum, esse, fui (to be): potis sum combines to form possum; potis es combines to form potes and so on.
See the chart below for a full listing of these forms.
- possum, posse, potui - to be able; can
- Present stem: N/A - since posse is built on the irregular verb esse, we do not have a regular present stem. Note when the forms use "pos-" and when they use "pot-".
- Perfect stem: potu- (reminder: all verbs, even irregular ones, form their perfect stem by dropping the -i from the 3rd PP: potui - i)
| Person | Present Tense | Imperfect Tense | Future Tense | |||
|---|---|---|---|---|---|---|
| Singular | Plural | Singular | Plural | Singular | Plural | |
| 1st Person | possum | possumum | poteram | poteramus | potero | poterimus |
| 2nd Person | potes | potestis | poteras | poteratis | poteris | poteritis |
| 3rd Person | potest | possunt | poterat | poterant | poterit | poterunt |
| Person | Present Tense | Imperfect Tense | Future Tense | |||
|---|---|---|---|---|---|---|
| Singular | Plural | Singular | Plural | Singular | Plural | |
| 1st Person | potui | potuimus | potueram | potueramus | potuero | potuerimus |
| 2nd Person | potuisti | potuistis | potueras | potueratis | potueris | potueritis |
| 3rd Person | potuit | potuerunt | potuerat | potuerant | potuerit | potuerint |
Nota Bene:
- Notice how similar the imperfect is to the pluperfect (poteram vs. potueram) and the future is to the future perfect (potero vs. potuero). That one letter "u" makes a huge difference.
- The perfect system of possum follows the same rules as all other verbs: perfect stem (3rd PP - i) + tense ending: potui - i = potu-
- Along with meaning to be able posse has the ability to be translated can. When using the translation can, the complementary infinitive is not introduced with to:
- Gladiator bene pugnare potest.
- The gladiator is able to fight well.
- The gladiator can fight well.
- Spectatores puerum videre non poterant.
- The spectators were not able to see the boy.
- The spectators could not see the boy.
- Gladiator bene pugnare potest.