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Third Declension Nouns, Third Conjugation Verbs, and Third Declension Adjectives… Oh My (Part I ?)

Thirds are difficult in Latin. Third declension is troublesome, third conjugation is perilous, and third declension adjectives are downright inconvenient. Just when you think you have a handle on Latin—after first and second declension nouns, verbs and adjectives—THIRD comes along and provides a jolt to your system. You start to wonder if you really understood Latin or whether that was just a figment of your imagination.


You did, in fact, understand Latin—it was not an illusion. Third in Latin is always harder than others, in my humble opinion. However, it is not insurmountable. You need to use the pegs in your memory—of other declensions and so on—to help you understand the disturbing third.


First of all, third declension endings are similar to first and second. The dative singular and ablative singular are vowels, the accusative singular ends in "m" (masculine and feminine), the genitive plural ends in "um", and dative and ablative plural are always the same. If you look at first, second, and third declensions side-by-side, the only ornery part is that the nominative has no set ending. Nevertheless, it helps you because if you see a word with a strange looking ending, it might be nominative singular of third declension. Neuter third declension nouns follow the neuter rule: nominative and accusative singular are always the same and nominative and accusative plural end in "a." Just like first and second declension, the genitive provides the stem (in general, for all stems, you look to the second form given in the vocabulary).


Third declension genders can be a bit tricky. You can utilize Henle’s SOX, ERROR and LANCET, or you can memorize each word individually (other books and dictionaries cite the gender for each word). Male roles are masculine and female roles are feminine. Places and abstract nouns, such as ideas, are usually feminine. To ameliorate confusion, you can make your flashcards in different colors to denote masculine, feminine, and neuter.


Third declension I-stem nouns are a subset of third declension. Masculine and feminine third declension I-stem nouns have –ium in their genitive plural. Most books teach I-stems all together. Henle is no exception. Memorize them together and maybe draw an eye on your flashcards to remember. Do not get bogged down by I-stems. I, myself, do not know why Samnite is an I-stem. It just is. Our plight is not to understand everything, but to memorize it. If I tried to understand every reason behind every concept in math and science, I would go mad. Do not get stuck in these concepts. The big picture is only that there are a few words that have –ium as their genitive plural. That is it.


Just remember, you are not the only person to think that the thirds in Latin are strange. Many before you have felt the same way. Do not panic; remember, Latin is a very logical language. It is much easier to apply the rules of Latin than it is to apply the rules of English (e.g., lead, led or elf, elves or roof, roofs). Utilize the memory pegs you already have and work from there.


If you would like me to write part II of the thirds (third conjugation verbs), please either “like” this post on Facebook, e-mail me (, or add a comment.


I wish you a blessed season of Thanksgiving!

TIERS: challenge
CATEGORIES: Articles, Classical Christian Education, Rhetoric Stage (ages 14 to 18)

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