The “With” Group
English phrases starting with the preposition “with” convey several different ideas. “With” can introduce a companion, as in “Ryan stayed with me the whole time.” It can show a tool that is used to accomplish something, as in “I fixed it with my hammer.” It can also describe the manner in which something is done, as in “They applauded the actors with great enthusiasm.” Although these ideas may sound all alike to you in English, they're actually quite different. Latin recognizes the differences and uses different grammatical constructions to express them.
The English preposition “with” can also mean the opposite of itself! “He fought with his brother.” Does that mean he fought alongside his brother or against him? There's no confusion in Latin. Cum fratre suō pugnā vit means that he fought with his brother at his side. If you mean “against,” you say “against.” Contrā fratrem suum pugnā vit.
Let's take a closer look at these distinctions that sound so alike in English. Consider this sentence: “The farmer was plowing the field with his son.” This sentence could mean two different things. Either Junior was helping Pop in preparing the field, or Pop was cruelly dragging Junior through the dirt. One understanding of the sentence makes a little more sense, even without a context. There are times, however, that you do need context to figure out what is meant.
Here is another example: “The master beat the slave with a stick.” It could mean two things, couldn't it? First, it could be that the master used the stick to beat the slave with. It could also be that of all the slaves, the one holding the stick got beaten. Latin has a grammatical way to clarify this confusion.
Different uses for the ablative case have formal names. The most common of these uses is the ablative of accompaniment. It uses the Latin preposition cum (with its object in the ablative case, of course) and shows exactly what its name suggests: accompaniment.
Vir cum multīs senā
Not all ablative case uses are introduced by a preposition. Some uses never have any prepositions at all. They just appear all by themselves. The most common of these ablative uses that doesn't require a preposition is the ablative of means.
The phrase “ablative of means” doesn't indicate its use as well as many other ablative usage names do. It shows the “means” by which something is done; that is, the tool used.
Mī les hostem gladiī interfē cit. (The soldier killed the enemy with a sword.)
The presence or absence of the preposition cum will guide your understanding.
There is one other ablative case use that usually employs the preposition cum. The ablative of manner shows the manner in which something is done.
Omnē s cum studiī clamā bant. (Everyone was cheering with enthusiasm.)
There are two peculiarities of the ablative of manner that occur when the noun in the phrase has an adjective with it. First, the adjective usually comes before the cum. Second, when there is an adjective, the cum becomes optional. (Without an adjective, you have to have the word cum.)
Omnē s magnī cum studiī clamā bant. (Everyone was cheering with great enthusiasm.)
Omnē s magnī studiī clamā bant. (Everyone was cheering with great enthusiasm.)
An ablative of manner phrase often sounds better when translated like an adverb: Everyone was cheering enthusiastically (cum studiō), or very enthusiastically (magnō cum studioō).