Latin THIRD DECLENSION Lesson
This is the most critical, pivotal lesson of your Latin career. With this lesson learnt the rest is just a
matter of filling in minor details (which are listed at the end of the lesson.) It is tricky to learn and to use
the THIRD DECLENSION and that is why it is so important to deeply understand it, starting right now!
Our Ontario government states that we need to learn the third declension (and even the following two!)
in grade 9:
By the end of the first course in a classical language, students will
recognize and correctly apply their knowledge of the following items
in various language activities.
Nouns
– all cases, numbers, and genders, declensions
1, 2, 3, 4, 5
Adjectives
– all cases, numbers, and genders, declensions
1, 2, 3
– agreement with antecedents (nouns,
pronouns)
Thus, we had better get going on it! 
The most important part of communication is to convey what is doing what to what. How, with what,
from what, to what, and why et cetera are all supplementary to these basic THREE:
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These three things are so important that it is with these three that we categorize most languages into
two major divisions. The two main divisions are Subject-Object-Verb (SOV) and Subject-Verb-Object
(SVO) languages. SVO languages need less morphology (modifying of words) to work as we know that
the noun in front of the verb is the subject and the one after the verb is the object. SOV languages have
more morphology since they need markers attached to their words to make it clear which word is the
subject and which is the object. Chinese, Mayan, and English are examples of SVO languages and Latin
and Korean are examples of SOV languages. There are languages that defy this kind of classification of
course too, examples being most indigenous American languages, such as Mohawk and Ojibwe. The
myriad of different ways languages have developed to express what is doing what to what is absolutely
BEWILDERING! When we talk about language families, we tend to mean languages that do this in
virtually the same ways. Thus, to a linguist, closely related languages like English, French and German
are hardly even different languages – as they work in almost the same exact ways in spite of different
sounds to their words. To a linguist, languages like Tagalog, Mohawk, Turkish, and English, which are
organized completely differently really ARE different!!! Sometimes apparently unrelated languages like
Chinese and English end up for whatever reason to function quite similarly, and that is just WEIRD!!!
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1. The doer (the SUBJECT)
2. What is being done (the VERB)
3. That which is having something done to it (the OBJECT)
Anyhow, Latin being an SOV language, learning the morphology of the nouns (and adjectives) is
absolutely fundamental to being able to make sense of the language.
Examples:
Language
Korean
Latin
Subject Markers
이, 는, 은, 가
Singular: a, us, um, u, es
Plural: ae, i, a, us, es
Object Markers
을, 를
Singular: Am, um, em, us, u, es
Plural: as, os, a, us, es
(The bolded endings you have already learned as parts of the 1f, 2m, and 2n declensions.)
A great thing about studying Latin is that you learn to handle a language that works quite a lot
differently from English or French, but it isn’t very hard because we get most of our words from it. It’s a
nice balance between being easy on the one hand and quite strange on the other. It is a perfect first
step into linguistics because you can learn to think very differently about language structure without
becoming overwhelmed with new vocabulary.
Okay, enough blah blah blah and let’s get to it! Let’s quickly go over the 1st and 2nd declensions and then
move on to master the 3rd set. We all learn best by DOING, so let’s DO!
We will need vocabulary to do this. Let’s use the words in the following chart to keep it simple:
Remember, in the dictionary, you can see the genitive singular ending for NOUNS after the comma,
since these can vary and need to be specified there. E.g. Regnum, i - kingdom.
For ADJECTIVES, the endings for all of Masculine, Feminine and Neuter Singular Nominative are given.
E.g. Gratus, a, um – pleasing.
For VERBS, there are 4 things given: 1. The 1st person singular present active indicative (e.g. perago – I
complete) 2. The infinitive (e.g –agere) 3. The 1st person singular perfect active indicative (e.g. –egi) 3.
The past (or sometimes another one if it’s irregular) participle (e.g. –actus). It is necessary to list all four
of these things since if you know these, you can fully conjugate the verb in all its tenses, moods, and
aspects according to the regular rules.
Which declension set are these from: 1 Feminine, 2 Masculine, or 2 Neuter?
If a noun or adjective:
Which Declension? 1f, 2m, or 2n
2
Julia, ae
Julius, i
Laetus, a, um
Maestus, a, um
Amo, -are, -avi, -atus
Elephantus, i
Taberna, ae
Forum, i
Vinum, i
Adjective, Verb, Noun or
something else?
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Word – translate it next to it
Do, dare, dedi, datus
Pecunia, ae
Cunctus, a, um
Valde
Simia, ae
non
Eo, ire, ivi/ii, itum
Sum, esse, fui, futurus
Video, videre, vidi, visus
Formosus, a, um
Here is your 1st and 2nd declensions chart to help you if you still need it at all:
Singular
Case
1 f.
2 m.
Nominative
-a
-us
-um
Genitive
-ae
-i
-i
Dative/Ablative
-ae/-a
-o
-o
Accusative
-am
-um
-um
Plural
Case
1 f.
2 m.
Nominative
-ae
-i
Genitive
-arum
-orum -orum
Dative/Ablative
-is
-is
-is
Accusative
-as
-os
-a
(n.)
(n.)
-a
Julia loves Julius. _____________________________________
Julia and Julius go to the market. _____________________________________
They go into a shop. _____________________________________
They see happy elephants. _____________________________________
The elephants are drinking wine with all the monkeys.
__________________________________________________________________________
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1.
2.
3.
4.
5.
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So, as a review of what you already know about Latin grammar, using the words above, and others if
necessary, translate the following INTO Latin. (Translating INTO Latin teaches you how the grammar
works much faster than vice versa.)
As you notice, the adjectives you used for the nouns all perfectly RHYME with them! That’s so
nice isn’t it, as it makes it easy to tell that they go together! But guess what, this all ENDS NOW with the
3rd declension! RAAAAAAAAAAAA! Now you get to learn why linguists are so respected – because
learning other languages which have different grammatical systems is NO JOKE!
Here are the 3rd Declension endings (I recommend copying them out a few times to get familiar
with them):
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The masculine and feminine decline the same way. Even though Latin nouns have strict gender
attached to them, in the 3rd declension the gender is not clear just by looking at them, so it is fair to say
that 3rd declension nouns are for things that the gender is not as important for. Some examples are
“nox, noctis” (f) - night, and “gladiator, -oris” (m) – gladiator. Nox is feminine and gladiator is masculine,
but if you think about it there is no special reason to think of nighttime as feminine and also, there were
female gladiators. We could get into a long philosophical discussion about why Latin might have
developed the 3rd, 4th and 5th declensions, but in the end, it just did, and we had better get on with
learning the language. The fun and utility is in using the language. Anyhow, the 3rd declension is a kind of
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Singular
Case
3 mf (n.)
Nominative
---- ---Genitive
-is -is
Dative/Ablative -i/-e -i/-e
Accusative
-em ---Plural
Case
3 mf (n.)
Nominative
-es -a
Genitive
-um -um
Dative/Ablative -ibus -ibus
Accusative
-es -a
sneaky one compared with the 1st and 2nd since you don’t know what gender it is unless you see an
adjective attached to it!
So, let’s see some examples. Please translate these into English:
1.
2.
3.
4.
5.
Nox laeta est. _________________________
Gladiator laetus est. _________________________
Nox maesta est. _________________________
Gladiator maestus est. _________________________
Gladiator et nox maesti sunt. _________________________
Please notice how the noun and the adjective going with it in each sentence DO NOT RHYME!
Now, look at the 3rd declension chart. What are 6 things that are the same as in the 1st OR 2nd
declension endings???
1.
2.
3.
4.
5.
6.
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
Also, what are 7 things about the 3rd declension that are different from the 1st or 2nd declension endings?
1.
2.
3.
4.
5.
6.
7.
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
_________________________
Let’s now learn some 3rd declension nouns and adjectives and start writing with them!
For dictionary entries, if it is a noun it is given in its nominative and then genitive singular forms,
followed by its gender. Thus: nox, noctis (f); gladiator, -oris (m); et cetera. It is important to realize that
the stem you see in the genitive singular form is the one you build all your other case endings onto.
Thus:
Nox, noct-is (f) – see how the stem changes from NOX to NOCT!!!
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If it is an adjective and the neutral singular form is the same it is listed in the same ways as nouns BUT if
it has a different nominative singular ending for its neutral form, it is given in its nominative singular m/f
form followed by its nominative singular NEUTRAL form. Thus: melior, melius (the “melius” being the
NEUTRAL singular nominative form); tristis, triste (the “triste” being the neutral singular nominative
form.) (By the way, don’t worry if you don’t understand this right now!!!  )
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Therefore, the accusative singular is NOCT-EM, the plural nominative and accusative is NOCT-ES etc…
NOUNS
Nominative Singular
Nox
Gladiator
Mater
Pater
Soror
Frater
Homo
Senator
Rex
Virtus
Dux
Urbs
Genitive Singular
Noctis
Gladiatoris
Matris
Patris
Sororis
Fratris
Hominis
Senatoris
Regis
Virtutis
Ducis
Urbis
Gender
F
M
F
M
F
M
M
M
M
F
M
F
English Meaning
Night
Gladiator
Mother
Father
Sister
Brother
Human being
Senator
King
Courage
Leader
city
ADJECTIVES
Dictionary Entry
Acer, acris, acre (notice: Nom. Sing. m/f, Gen.
Sing., Nom Sing. n are given here because they are
all different)
Prudens, prudentis
Ingens, ingentis
Fortis, forte
Felix, felice
Tristis, triste
Vehemens, vehementis
Velox, velocis
English Meaning
Sharp/harsh
Wise
Large/huge
Strong
Happy
Sad
Violent
fast
Assignment 1
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1. The strong mother loves the happy father.
______________________________________________________________________________
2. The sad brother loves his wise sister.
______________________________________________________________________________
3. The violent gladiator has courage.
______________________________________________________________________________
4. The huge gladiator is the father of my sister.
______________________________________________________________________________
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Using the third declension nouns and adjectives given here as much as possible, translate the following
into Latin:
5. A wise king is the strong leader of the happy city.
______________________________________________________________________________
6. The gladiator is huge, strong and fast!
______________________________________________________________________________
7. The wise king gives a large city to the huge, strong and fast leader.
______________________________________________________________________________
8. Strong cities are happy cities.
______________________________________________________________________________
9. Gladiators are violent human beings.
______________________________________________________________________________
10. The happy senators are standing with the huge gladiators.
______________________________________________________________________________
You have to get a perfect mark on these to go onto the next section.
/20 marks (2 per each sentence.)
Assignment 2
Now, translate the following, using ALL the words you know. Please notice that you will often have a
first or second declension word going with a 3rd declension one. Here are some Latin to English
examples:
1. Pater laetus matrem laetam amat.
Translate it here: ____________________________________________________________________
2. Dux laetus urbis maestae cunctos simias et elephantos habet et non populis dat.
Translate it here: ____________________________________________________________________
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3. A man gives money to the emperor.
______________________________________________________________________________
4. The emperor makes the man a senator.
______________________________________________________________________________
5. The man is a happy senator.
______________________________________________________________________________
6. The senator puts on (i.e. “gives”) games for the people in the coliseum.
______________________________________________________________________________
7. The happy people cheer for the great senator.
______________________________________________________________________________
8. The entire city watches the games happily.
______________________________________________________________________________
9. Everyone cheers for the gladiators.
______________________________________________________________________________
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Now for English to Latin:
10. Now the senator has no money.
______________________________________________________________________________
11. The emperor sends him away from the senate. (i.e. kicks him out of it!)
______________________________________________________________________________
12. He is sad and miserable.
______________________________________________________________________________
13. He sees a beautiful woman.
______________________________________________________________________________
14. They love each other. (Think about how to express this in Latin – it’s short and effective.)
______________________________________________________________________________
15. They are both very happy now!
______________________________________________________________________________
You have to, and will, get a perfect mark on these to continue on.
/30 marks (2 per each sentence.)
GRAND TOTAL /50 NAME:_________
A preview of what is left to learn about Latin grammar:
PARTICIPLES:
ns or nt = ing (followed by THIRD DECLENSION endings!!!), so:
amans = loving
amantis = of a loving thing/person
t = ed, so:
amata = a female thing who is loved
amatus = a male thing who is loved
tur = will soon be, so:
amatura = a female thing who will soon be loved
amaturus = a male thing who will soon be loved
nd = should be, so:
Amanda = a female thing who should be loved
Amandus = a male thing who should be loved
Examples:
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amans - loving; the loving one (= lover)
sequens - following
sapiens - wisely knowing, the knowing one, the sage
oriens - rising
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Present Active Participle (this one uses the THIRD DECLENSION!!!):
(Declined in 3rd, so “amans” becomes “amantis” in the genitive singular, etc...)
Past Passive Participle:
amata - loved; having been loved, the beloved
paratus - prepared
capti - [those] having been captured; taken
armati - armed
Past Active Participle (only for deponent verbs):
secutus - having followed
locuta - having spoken
Future Active Participle:
morituri - about to die, going to die
futura - about to be
Future Passive Participle (= the "Gerundive"):
delenda - about to be destroyed, to be destroyed
agenda - [things] to be done
corrigenda - [things] to be corrected
memoranda - [things] to be remembered
4th and 5th DECLENSIONS: (Please notice how the 4th is basically a mix of 2nd and 3rd and 5th is very similar
to 3rd!) Examples: SPES (hope) and RES (thing) are 5ths and MANUS (hand) and CORNU (horn) are 4ths.
Singular
Case
4 m.
4 n.
5 f.
Nominative -us
-u
-es
Genitive
-us
-us
-ei
Dative
-ui
-u
-ei
Accusative
-um
-u
-em
Ablative
-u
-u
-e
Locative
-i
?
?
Vocative
-us
-u
-es
Case
4 m.
4 n.
5 f.
Nom/Voc
-us
-ua
-es
Genitive
-uum
-uum -erum
Plural
-us
-ua
-es
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Accusative
9
Dat/Abl/Loc -ibus, -ubus -ibus -ebus
Ontario Curriculum References (Grade 9 Latin):
Overall Expectations
By the end of Level 1, students will:
• read and demonstrate an understanding of simple texts in the classical language
Overall Expectations
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By the end of Level 1, students will:
• write simple phrases and sentences in the classical language, using grammatical
forms and vocabulary appropriate to the level