Home » Curriculum » Trivium » TRV-221 Latin Grammar I » Latin Grammar I, Lesson 10. General Rules for Noun Declensions

Latin Grammar I, Lesson 10. General Rules for Noun Declensions

To complete this lesson, complete the following tasks:

  1. Study the Lesson for mastery.
  2. Complete all lesson Memory Work.
  3. Complete the lesson Assessment.

Lesson

In lesson 03, we learned that there are five declensions of Latin nouns. We learned:

The Declensions of nouns are five.

The First declension, whose genitive singular is ended with the diphthong -AE, as musamusae.
The second declension, whose genitive singular is ended with the letter -I , as dominusdomini.
The third declension, whose genitive singular is ended with (the) syllable -IS , as sermosermonis.
The fourth declension, whose genitive singular is ended with the syllable -US , as sensussensus.
The fifth declension, whose genitive singular is ended with the letters E and I, as diesdiei.

Through the next ten lessons, we will study all the details of these five declensions of Latin nouns.  In this lesson, we will study eight general rules that will help us prepare to study them.  These can be divided into two groups:  (1) rules concerning composite nouns, and (2) rules concerning similar cases.

I. Concerning Composite Nouns

In lesson 03, we learned about simple and composite nouns:

The Figures of nouns, of pronouns, of verbs, of participles, of prepositions, of adverbs, of conjunctions are two: Simple, as prudens; and Composite, as imprudens.

In the declension of simple nouns, we will learn the nominative (or “rectus) case of a noun, and then how the endings of that noun change in its different cases.  When we form composite nouns, however, declension can be a little confusing.  To avoid this confusion, Fr. Alvarez gives us four general rules to help us understand how composite nouns are declined.

1. Nomina composita fere instar simplicium declinantur, ut virviritriumvirtriumviri;  prudensprudentisimprudensimprudentisAt quaedam id non servant, ut sanguissanguinisexsanguisexsanguis, non exsanguinis;  capricornus, capricorni; centimanus, centimana, centimanum, quamvis composita a cornus, cornus et manus, manus;  sic unimanus et anguimanusquiesquietisrequiesrequiei et requietis;  pubespubisimpubes vel impubis is et eris; portusportus,  angiportumangiporti genere neutro.

In the first rule, we learn that composite nouns are, in general, declined like the simple nouns from which they are formed, as the compound noun triumvir makes its genitive case triumviri, and is declined just like the simple noun virviri from which it is composed.  Again, the composite noun imprudens makes its genitive case as imprudentis, and is declined like the simple noun prudensprudentis.  So, it is generally good to assume that a composite noun will be declined like the simple noun it is composed from.

We do need to be careful, however, because we will find certain nouns that are not declined like the simple nouns from which they are composed.  For example, the composite noun exsanguis makes the genitive case as exsanguis, rather than exsanguinis as the simple noun sanguis, sanguinis does.  Likewise, the composite noun capricornus makes capricorni and the adjective centimanus is declined with three endings as centimanuscentimanacentimanum though they are composed from the fourth declension nouns cornus, cornus and manusmanus.  Likewise, from the simple noun quiesquietis, we find both requies, requiei and requiesrequietis.  From pubespubis, we find impubes declined in some places as impubis but elsewhere as impuberis.  From the simple fourth declension noun portusportus,  we find the poet Terence using the composite noun angiportumangiporti in the neuter gender, but in another place, using angiportusangiporti or angiportusangiportus in the masculine gender.

In the first rule above, we learned about composite nouns which are composed of a noun and a preposition or adverb.  In these words, only the noun is declined.  In some composite nouns, however, two declinable nouns are joined, and both may be declined. This leads us to ask, “Would both nouns be declined, or only one?”.  Fr. Alvarez answers this question in the next two rules.

II. In compositis, rectus tantum casus declinatur ut tribunus plebistribuni plebistribuno plebistribunum plebis, etc.  Huc spectant senatusconsultumiurisperituspaterfamilias atque eiusdem generis alia.

Here we learn that in some composite nouns, we will find one noun in the nominative case and the other in another case.  In such composite nouns, only the noun in the nominative case will be declined, as in tribunus plebistribuni plebistribuno plebistribunum plebis, etc.  Here the ancients also consider the composite nouns senatusconsultumiurisperituspaterfamilias and others of this kind.

III. Si nomen ex duobus rectis copuletur, uterque declinabitur, ut respublica, reipublicae,  reipublicae, rempublicamiusiurandumiurisiurandiiuriiurando, etc.

Here, we learn that if a composite noun is composed of two nominatives, then both of them shall be declined according to their own declensions.  For example, the noun respublica is composed of the nominatives nouns res (5th declension)  and publica (1st declension).  Both of these change forms in the declension of this composite noun, as: respublicareipublicaereipublicaerempublicam.  The same is true with the composite noun iusiurandum, composed of the noun ius (3rd declension) and the participle iurandum (2nd declension), as: iusiurandum, iurisiurandiiuriiurando, etc.

IV. Excipitur alteruter, cuius posterior tantum pars plerumque solet declinari.

Fr. Alvarez here notes that this third rule does not always apply, since the pronoun alteruter is excepted, whose posterior part alone is generally accustomed to be declined.  This is worth noting because this pronoun is very commonly used and will be seen often in our readings.

II.  Concerning Similar Cases

As we begin the study of the declensions of Latin nouns, we will need to learn twelve different forms for every example noun:  one singular form and one plural form for each of the six cases.  If there was only one example noun for each of the five declensions, that would be 60 forms to memorize, but there are actually many more examples nouns that this.  We will need to memorize hundreds of forms to learn the declensions, and Fr. Alvarez here gives us a few rules that will help to make this easier.

V. Nomina neutra tres casus habent similes: nominandi, accusandia, vocandi; qui numero multitudinis a litera terminantur praeter ambo et duo.

In this first rule, we learn that the forms of the Nominative, Accusative and Vocative cases are always the same in neuter nouns.  So, when we learn the nominative singular form for a neuter noun, we will know its accusative and vocative singular form as well.  The same is true in the plural number.  Moreover, in the plural number these three cases always end in the letter –(except in the nouns ambo et duo).  That’s a very helpful rule!

VI. Vocativus singularis quartae et quintae similis est nominativa: sensusO sensusdiesO dies.

In this second rule, we learn that in the fourth and fifth declension, the vocative case is always the same as the nominative in the singular number.  So, if we know the fourth declension noun sensus, we know that its vocative form is O sensus.  Likewise, in the fifth declensoin, if we know dies, we will know that the vocative form is O dies.

VII. Nominativus et vocativus multitudinis similes sunt: musaeO musaevirtutesO virtutes.

In  this third rule, we learn that the nominative and vocative plural forms are the same in every declensions.  Thus, in the first declension, the plural nominative is musae, so the plural vocative will be O musae.  Likewise, in the third declension, the plural nominative is virtutes, therefore the plural vocative will be the same: O virtutes.

VIII.  Dativus et ablativus numeri pluralis similes sunt. musis a musis. virtutibus a virtutibus.

In this fourth rule, we learn that the dative and ablative forms of the plural number are always the same.  So, if the plural dative form is musis, then the plural ablative will be a musis.  If the plural dative is virtutibus, then the plural ablative will be a virtutibus.  This, again, will help us greatly in our memory work.

Summary

In our next ten lessons, we will study all of the forms of the five declensions of Latin nouns.  In this lesson, we have learned eight general rules that will help us to avoid confusion and memorize the forms more easily.

Memory Work

  1. How are composite nouns declined in general?
    Composite nouns are, in general, declined like the simple nouns from which they are composed.
  2. How are composite nouns declined when composed of only one nominative case?
    Composite nouns composed of only one nominative case are declined in that one noun only.
  3. How are composite nouns declined when composed of two nominative cases?
    Composite nouns composed of two nominative cases are declined in both.
  4. When are composite nouns composed of two nominative cases not declined in both?
    Alteruter
    , despite being composed of two nominatives, is only declined in the, alter.
  5. What observation about neuter nouns can help us to learn the declensions of neuter nouns more easily?
    The nominative, accusative and vocative cases are always the same (in each number) in neuter nouns; these cases always en in -a in the plural number.
  6. What observation about nominative and vocative cases can help us to learn the declensions of 4th and 5th declension nouns more easily?
    The nominative and vocative cases of the singular number are always the same in 4th and 5th declension nouns.
  7. What observation about nominative and vocative cases can help us to learn the declensions of all declension more easily?
    The nominative and vocative cases of the plural number are always the same in all declensions.
  8. What observation about dative and ablative cases can help us to learn the declensions of all declension more easily?
    The dative and ablative cases of the plural number are always the same in all declensions.

Assessment

Latin Grammar I, Lesson 10 Exam