Via lata ad forum ducit.

Because via is in the nominative singular, which is the case normally used for the subject.

• via = road / street / way
• it is a first-declension feminine noun
• the verb ducit is singular, so via fits as the singular subject: the road leads

Because lata is an adjective agreeing with via.

In Latin, adjectives must match the nouns they describe in:

• gender
• number
• case

Since via is feminine singular nominative, the adjective must also be feminine singular nominative:

• via = feminine singular nominative
• lata = feminine singular nominative

So via lata means broad road or wide road.

Because ad takes the accusative case, and forum is the accusative singular of forum.

This can be confusing because forum is a neuter noun, and in many neuter nouns:

• nominative singular = accusative singular

So forum can be either nominative or accusative in form, but after ad, it must be understood as accusative.

Ad plus the accusative usually expresses motion toward a place.

So ad forum means:

• to the forum
• or toward the forum

It shows the destination or direction of the action.

Ducit is:

• third person singular
• present tense
• active voice
• indicative mood

It comes from ducere, meaning to lead.

The ending -it tells you he/she/it leads. Here the subject is via, so the sense is the road leads.

Because classical Latin does not have articles like English the and a/an.

So via lata can mean:

• the broad road
• a broad road
• simply broad road

Which English article you use depends on context and natural translation.

Because that is a very common Latin word order.

Latin often places:

• noun first
• adjective after it

So via lata is completely normal. Latin word order is more flexible than English because the endings show the grammar. You could change the order for emphasis, but the basic meaning would stay the same.

Yes.

Since Latin has no article, both are possible unless the wider context makes one clearly better. A learner should get used to the idea that Latin often leaves this choice to the translator.

Because the verb ending already includes the subject information.

In English, we need it leads.
In Latin, ducit already means he/she/it leads.

So Latin often leaves subject pronouns unstated unless they are needed for emphasis or contrast.

No. In this sentence, ducit is used with a phrase of direction instead.

So the structure is:

• via lata = subject
• ducit = verb
• ad forum = destination/direction

The idea is the broad road leads to the forum, not the broad road leads someone.

Because ad marks movement toward a place.

If the sentence meant in the forum, Latin would normally use a different construction, such as:

• in foro = in the forum

So:

• ad forum = to/toward the forum
• in foro = in the forum

Yes. Via can mean:

• road
• street
• route
• way
• sometimes even a more abstract method or means

But in Via lata ad forum ducit, the presence of ad forum makes the literal sense road/street the most natural one.