Latin principal parts: three forms for each verb
In short
Every Latin verb has three principal parts: the present stem (first person singular present, for example moneo), the perfect stem (first person singular perfect, monui) and the participle stem (perfect passive participle, monitum). All tenses are formed from them. The present stem is regular; the other two must be learned. Disce ludens I practices them in lesson 30, Disce ludens II in lesson 30 with 328 common verbs.
The three principal parts in examples
| Infinitive | Present stem | Perfect stem | Participle stem | Meaning |
|---|---|---|---|---|
| audire | audio | audivi | auditum | to hear |
| monere | moneo | monui | monitum | to warn |
| complere | compleo | complevi | completum | to fill |
| dare | do | dedi | datum | to give |
| stare | sto | steti | statum | to stand |
| abire | abeo | abii | abitum | to go away |
| accipere | accipio | accepi | acceptum | to receive |
What the tenses are formed from
- Present stem: present, imperfect, future I, present and imperfect subjunctive, present infinitive, imperative and the passive forms of these tenses. The present stem is always there and can be read from the present tense.
- Perfect stem: perfect, pluperfect and future perfect in the active, plus the perfect and pluperfect subjunctive in the active (laudaverim, laudavissem).
- Participle stem: the perfect passive participle (laudatus), which gives the perfect, pluperfect and future perfect in the passive (laudatus est), and the supine (laudatum).
Regular or not?
The present stem can always be read from the basic form. The other two are not predictable for many verbs. Common patterns still help:
- a-conjugation: perfect ending in -avi, participle in -atum (laudavi, laudatum).
- e-conjugation: perfect usually in -ui, participle in -itum (monui, monitum).
- i-conjugation: perfect in -ivi or -ii, participle in -itum (audivi, auditum).
- Consonant-stem verbs are often irregular: video, vidi, visum; curro, cucurri, cursum.
Practising principal parts
Disce ludens enters the three forms in three fields: present stem (1st sg. present), perfect stem (1st sg. perfect) and participle stem (perfect passive participle or supine). Disce ludens I practices the principal parts of common verbs in lesson 30 with 98 cards; Disce ludens II does so in lesson 30 with 328 verbs.
Try it
A real exercise from Disce ludens:
Disce ludens I · Lesson 30 · Principal parts of common verbs, card 3
complere (to fill): the present stem is compleo. What is the perfect stem?
Error points: 0
© Disce ludensWhat Disce ludens does – and what it doesn’t
What Disce ludens does
- Practices the principal parts of common verbs: Disce ludens I in lesson 30, Disce ludens II in lesson 30 with 328 verbs.
- Enters each form in its own field, with graded hints.
- Links the principal parts to the tenses formed from them.
What it doesn’t do
- Is not a list of all Latin verbs.
- Does not explain the exceptions of every irregular verb.
- Does not show vowel length marks (macrons).
Frequently asked questions
What are principal parts?
The three basic forms of a verb: present stem (moneo), perfect stem (monui) and participle stem (monitum). All tenses are formed from them.
Do I have to learn the principal parts by heart?
Yes, for the forms that cannot be predicted. Without them you will not recognize perfect and participle forms in a text.
Which principal part is already in the basic form?
The basic form (for example moneo, monere) contains the present stem. The other two principal parts must be learned in addition.
Which tenses are formed from the participle stem?
The perfect, pluperfect and future perfect in the passive, the perfect passive participle itself and the future participle (laudaturus).