In the twenty-seventh class of the Latin from Scratch course, we’ll study one of the (initially) most confusing and complex words: the conjunction cum, which we already know as a preposition.
I explain everything in the following video (⏳ 15m 07s ⌛):
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Contents
Summary of the syntax of CUM
The word cum has many different functions in Latin, some of them very frequent, which is why we need to learn how to identify the specific value in a given text.
Let’s start by summarizing the syntax of cum on a table:


CUM as an ablative preposition
When the word cum is followed by a word in the ablative case, most of the times it will be a preposition which introduces an adverbial of company with, or hostile company against.
Caesar cum equitibus venit.
Caesar came with the cavalrymen.
Nautae cum piratis pugnant.
The sailors fight against the pirates.
However, we might find the word cum followed by ablative with one of the functions we will study in a moment. In this case, it is just a coincidence that we have cum + ablative: the ablative is independent from cum and it is any other kind of adverbial.



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You should also take into account that there might be a genitive between cum and its ablative.
Romani cum Vercingetorigis militibus pugnant.
The Romans fight against Vercingetorix’s soldiers.
CUM as a time conjunction
It can be the connector introducing an adverbial subordinate clase of time “when”. This is the case only when the verb of the subordinate clause is in the indicative mood.
Cum Caesar in Galliam venit, quattuor legiones habebat.
When Caesar came to Gaul, he had four legions.
In the same syntactic context, the conjunction cum might be emphasized by the word primum (thus cum primum), which adds immediacy. We can translate it as as soon as.
Narrative CUM
This is the most common structure, but it only appears when the verb of the subordinate clause is in the subjunctive mood, specifically imperfect or, less frequently, pluperfect.
The term narrative cum (or historical cum) is a convenient way to call a construction with 2-3 simultaneous adverbial values: time, manner, cause. The translation into English should try to reflect all of them.
With imperfect
When the subordinate verb is imperfect subjunctive, the action described has happened very shortly before the main action.
Most of the times, English translates it just as when, but do try to see the difference between narrative cum and temporal cum:
Cum hostes videret, Caesar iussit impetum facere.
When/Since/Because he saw the enemies, Caesar ordered to attack.



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With pluperfect
In this case, the action described by the pluperfect has happened clearly before the main action. In English we will translate it as a pluperfect (but sometimes as a simple past, depending on the context and what feels right).
Cum hostes vidisset, Caesar iussit impetum facere.
When/Since/Because he had seen the enemies, Caesar ordered to attack.
Other less common uses of CUM
They are not as frequent, so most of the times we should begin by just trying to select one of the above. In any case, let’s briefly summarize the other functions if cum as a connector introducing adverbial subordinate clauses:
- Causal conjunction, only if the subordinate verb is in the present subjunctive or, less frequently, perfect subjunctive.
- Concessive conjunction, the rarest, but easy to spot, since in the main clause there is some particle such as tamen, attamen, nihilominus, etc.
The syntax of cum is a hard topic which really needs to be practiced, so let’s go!
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