Senator prudens senatui decretum novum proponit.

Senatui is dative singular of senatus, meaning to the senate or for the senate.

In this sentence, proponit means puts forward / proposes, and the person or group something is proposed to often goes in the dative in Latin. So:

• senator = the subject
• decretum novum = the thing being proposed
• senatui = the recipient, to the senate

So the structure is basically:

The wise senator proposes a new decree to the senate.

Because prudens is a third-declension adjective, and its nominative singular masculine and feminine form is simply prudens.

It agrees with senator in:

• gender: masculine
• number: singular
• case: nominative

But agreement in Latin does not mean the endings must look the same. It means the words match grammatically, even if they come from different declensions.

So:

• senator = nominative singular masculine
• prudens = nominative singular masculine

They match correctly.

You know this mainly from the nominative case and the verb ending.

• senator is nominative singular
• prudens agrees with it and describes it
• proponit means he/she/it proposes, which is 3rd person singular

That makes senator prudens the natural subject: the wise senator.

Meanwhile:

• senatui is dative
• decretum novum is accusative

So those are not the subject.

Because it is the direct object of proponit.

The senator is proposing what?
Answer: decretum novum = a new decree

In Latin, the direct object usually goes in the accusative case.

So:

• decretum = accusative singular
• novum = accusative singular, agreeing with decretum

Yes, it could come before.

Latin word order is more flexible than English because the endings show the grammar. So both of these are possible:

• decretum novum
• novum decretum

Both mean a new decree.

In many Latin sentences, adjective position can create slight differences in emphasis or style, but here either order would be grammatically fine. The version given is perfectly normal.

Proponit is:

• 3rd person singular
• present tense
• active voice
• indicative mood

Its dictionary form is propono, proponere, proposui, propositum, meaning to put forward, propose, set forth.

So proponit means:

• he proposes
• she proposes
• it proposes

In this sentence, the subject is senator, so the meaning is the senator proposes.

Classical Latin has no articles like English the or a/an.

So senator can mean:

• a senator
• the senator

And decretum novum can mean:

• a new decree
• the new decree

You figure out which is best from context. In a simple teaching sentence like this, English often uses the wise senator proposes a new decree to the senate, but Latin itself does not mark that distinction.

Yes. Because Latin uses case endings, the sentence can be rearranged much more freely than English.

For example, these would still mean basically the same thing:

• Senator prudens senatui decretum novum proponit.
• Senatui senator prudens decretum novum proponit.
• Decretum novum senator prudens senatui proponit.

The endings still show:

• senator = subject
• senatui = indirect object
• decretum novum = direct object
• proponit = verb

Different orders can change emphasis, but not the basic grammatical relationships.

Yes, senatui is from senatus.

Senatus is a 4th-declension noun. Its dative singular is senatui.

That may look unfamiliar if you are used to 1st- and 2nd-declension nouns, but it is a normal 4th-declension pattern. Some important forms are:

• senatus = nominative singular
• senatus = genitive singular
• senatui = dative singular
• senatum = accusative singular

So the -ui ending is a clue that this is a 4th-declension dative singular form.

Prudens often means:

• wise
• prudent
• sensible
• judicious

So it describes the senator as someone acting with judgment or foresight. Depending on context, English might translate it in slightly different ways.

Because proponit is already a fully conjugated verb. It already tells you:

• the action: propose
• the tense: present
• the person: 3rd
• the number: singular

English often needs a subject pronoun, but Latin verb endings already contain that information. So proponit by itself means he/she/it proposes.

Once you add senator, the subject becomes explicit: the senator proposes.

Because novum agrees with decretum in:

• case: accusative
• number: singular
• gender: neuter

That agreement shows they belong together.

It does not match:

• senator, which is nominative masculine singular
• senatui, which is dative singular
• prudens, which is nominative singular here

So decretum novum clearly means new decree.

Yes. It is a very common and useful pattern:

subject + indirect object + direct object + verb

Here that gives:

• Senator prudens = subject
• senatui = indirect object
• decretum novum = direct object
• proponit = verb

A native English speaker may want to translate in a more English-like order:

The wise senator proposes a new decree to the senate.

That is often the easiest way to understand the Latin structure.