Download this guide to the third and fourth conjugations

A short guide to the third and fourth conjugations
We have learned two different groups of verbs, or conjugations, based on the way
their stems look like. To determine the stem of a verb, we remove the -re ending from
the infinitive. Thus, a verb like laudare (“to praise”) has a stem that ends with the vowel
a. All verbs with a stem ending in a belong to the first conjugation; to the second
conjugation belong verbs ending in , such as
re. To conjugate these verbs, we
simply take the stem and add the personal endings:
voca + mus
The fourth conjugation
Latin has two additional conjugations; let’s begin with the fourth conjugation. This
group of verbs has a stem ending in , such as
re or
re. Like the first two
conjugations, we add the personal endings to the stem to conjugate:
re (“to feel, sense”)
+ mus (“we feel”)
As an exception to this rule, however, the third person plural requires the addition of
the vowel u between the stem and the personal ending:
Example: senti + u + nt (“they feel”)
The third conjugation
Verbs belonging to the third conjugation have infinitives that end in -ere (note that the
first e is short, unlike verbs of the second conjugation), such as agere (“to do”) and
facere (“to make”). Unlike the first, second, and fourth conjugations, verbs belonging to
the third conjugation have a stem that ends on a consonant:
Example: agere (“to do”)
Stem: ag
In order to make the pronunciation easier, the vowel i is added to the stem when the
personal ending begins with a consonant: that is to say, before every personal
ending, except the first person singular:
1st sing.: ag + o
2nd sing.: ag + i + s
Another exception is the third person plural, where the letter u is added instead:
ag + u + nt
Some verbs of the third conjugation behave similarly to those of the fourth conjugation
when they are conjugated. A verb like capere, for instance, has the vowel i before every
personal ending:
Example: capio (“I take”)
The third person plural has both the i and the u:
capiunt
These verbs are known as the “third conjugation -io verbs,” and when they are
conjugated in the present, imperfect, and future tense, they look identical to fourth
conjugation verbs. To know how to conjugate a verb of the third conjugation, you must
know the first two principal parts of the verb. If you know the principal parts facio,
facere, you know:
1. It belongs to the third conjugation, because the infinitive ends on -ere (with a
short e)
2. It is an an -io verb, because the first principal part ends in -io
Exercises
Now try to give the required forms of the following verbs (present tense):
1.
2.
3.
4.
5.
6.
rego, regere (3 pers. plural):
finio, finire (2 pers. singular):
facio, facere (3 pers. plural):
emo, emere (1 pers. plural):
pario, parere (3 pers. singular):
condo, condere (2 pers. plural):