Orator in contione de pace dicturus est.

Because orator is the subject of the sentence: it is the person who is going to do the action.

Its dictionary form is orator, oratoris (masculine), and the nominative singular is orator.

So:

• orator = the speaker / orator
• it is nominative because it is the one about to speak

Contione is ablative singular, and in with the ablative often means in, on, at a place.

So in contione means in the assembly / at the public meeting.

This is a normal Latin prepositional phrase:

• in + ablative = location
• in + accusative would usually mean motion into something

Here there is no motion; the speaker is located in the assembly, so Latin uses in contione.

Because after in meaning location, Latin uses the ablative.

The noun is:

• nominative: contio
• ablative: contione

So:

• contio = assembly as the subject form
• in contione = in the assembly

A learner often sees the dictionary form and expects it to stay the same, but Latin changes noun endings according to case.

Because the preposition de takes the ablative.

De often means:

• about / concerning
• sometimes from / down from, depending on context

Here it means about, so:

• de pace = about peace

The noun is:

• nominative: pax
• ablative: pace

So the ending changes because de requires the ablative.

Because the verb idea here is not to say peace but to speak about peace.

Latin often uses de + ablative to express the topic of speech, thought, writing, or discussion.

So:

• de pace dicere = to speak about peace
• not pacem dicere

Using de makes the relationship clear: peace is the topic, not the thing directly acted on.

Dicturus est is a combination of:

• the future active participle: dicturus
• the present tense of sum: est

Together they form what is often called the active periphrastic.

Basic idea:

• dicturus est = is going to say / is about to say / intends to say

It often expresses a future action with a sense of intention, readiness, or imminence, not just plain future time.

It could use dicet, but the meaning would be a little different.

• dicet = he will speak / say
• dicturus est = he is going to speak / is about to speak / intends to speak

So dicturus est is more vivid and often more personal. It can suggest that the action is already planned or immediately forthcoming.

A native English speaker can think of it as the difference between:

• He will speak
• He is going to speak

They overlap, but they are not exactly the same.

Because it agrees with orator.

Participles behave like adjectives, so they must match the noun they describe in:

• gender
• number
• case

Since orator is:

• masculine
• singular
• nominative

the participle is also:

• dicturus = masculine singular nominative

If the subject were feminine, plural, or in another case, the participle would change form.

Because the future active participle is built from the supine stem, not directly from the present stem.

For dico, dicere, dixi, dictum:

• the supine is dictum
• the stem is dict-
• so the future participle is dicturus

That is why Latin gives:

• dicturus, -a, -um = about to say / speak

This is a common pattern:

• amo → amaturus
• moneo → moniturus
• rego → recturus
• dico → dicturus

In this sentence, English often translates it as speak, even though the basic verb dico is often taught as say.

That is because with a phrase like de pace, Latin is expressing public speaking or speaking on a topic:

• de pace dicere = to speak about peace

So depending on context, a natural translation could be:

• The orator is going to speak about peace...
• The speaker is about to talk about peace...

This is a good reminder that Latin verbs do not always match one single English verb in every context.

Latin word order is much freer than English word order because the endings show the grammatical relationships.

So Latin can say:

• Orator in contione de pace dicturus est

without needing a fixed subject-verb-object order like English.

This order is quite natural:

• Orator first: introduces the subject
• in contione: gives the setting
• de pace: gives the topic
• dicturus est at the end: saves the verbal idea for the close of the sentence

Latin often puts the main verbal element near the end, especially in formal or literary style.

Not exactly. Contio usually refers to a public assembly or meeting, especially one where someone addresses a group.

So in contione suggests a public-speaking setting:

• an assembly
• a gathering of citizens
• a place where an orator makes a speech

It is not simply any random crowd, and it is not exactly the same thing as the Senate. The word strongly suits the presence of an orator.

Yes. The future active participle + sum is a standard Latin construction.

You will often see it when Latin wants to express:

• intention
• expectation
• a future action viewed as impending
• what someone was going to do

For example:

• venturus est = he is going to come
• scripturus sum = I am going to write
• pugnaturi erant = they were going to fight

So dicturus est is a very useful pattern to learn early.