My question is this: which words or forms are most commonly used in Latin literature? When Caesar fights against the Gauls, is he fighting contra Gallios or contra Gallos? Are the people the populi Galli or populus Galliorum? When speaking the Gallic native tongue, is one speaking Gallice or Galle?
Sorry if this is so basic a question…but having never read Caesar I honestly don’t know what’s proper here.
Two of these four forms are really the same: Galli, -orum is just the plural of Gallus, -a, -um. So Caesar would fight contra (or in) Gallos (none of these forms would produce “Gallios”). And the people themselves would be referred to as the “Galli” (if you wanted to add “populus” there are various combinations that might show up, although “populus” is generally not put into the plural to mean “people” - it already means “people” in the singular. In the plural it means “groups of people”). I imagine that they would speak “Gallice” as the “Gallus” adjective (if indeed it can be called an adjective) seems to be applied exclusively to the people. “Gallus” in the singular would correspond to our “A Gaul”, “Galli” in the plural would correspond to our “THE Gauls”, and “Gallicus -a -um” to our adjective “Gaulish” (which is what we call the language).
In fact they are all different, at least grammatically speaking.
Gallia, -ae (noun f) is the country, region of Gaul (more or less modern France)
Gallicus, -a, -um (adj.) of the Gauls, Gallic as in “De bello gallico? meaning the Gallic war.
Now the more difficult ones:
Gallus, -a, -um (adj.) Gallic, a Gaul. This is an adjective meaning that something is Gallic, it can be a sword, a house, a man and so one. If it is a person the word “man? or “woman? can be omitted and then (for me at least, probably due to lack of grammar knowledge) it works as a noun.
Galli, -orum (noun m. pl.). The people of Gaul, the Gauls.
In the D’Ooge book this distinction appears too in other people names like:
Romani, -orum (noun m. pl.)
Romanus, -a, -um (adj.)
Legionarii, -orum (noun m. pl.)
Legionarius, -a, -um (adj.)
And so one.
This distinction doesn’t make much sense to me but as I already said it is probably because my lack of grammar knowledge.
The only difference I have found it is with the genitive and vocative singular cases of these adjectives that end in –ius that follow the general rule (genitive as –ii, and vocative as –ie) instead of the particular rule for the nouns (genitive as –i, and vocative as –i). Since this particular rule only exists in a limited epoch I can’t see much difference.
It may be helpful to know that Roman grammarians didn’t distinguish between adjectives and nouns. I’m not sure it’s possible to make a worthwhile distinction between Gallus-a-um as adjective and Galli, -orum as noun. After all, doesn’t Galli imply Galli homines? Of course, when an adjective is used substantively for long enough it tends to act like a noun; that is, it takes on an identity of its own without depending upon the noun that was originally understood. For instance, think of how Latin deals with seas and oceans: Atlanticus (Oceanus), Hadriaticum (Mare). Their gender supposes the noun they modify, since they are technically adjectives, but they can be used independently.