In foro poculum ex argento videmus.

Because the preposition in takes the ablative when it means in or on in the sense of location.

• forum = forum, marketplace
• foro = in the forum / at the forum

So in foro means in the forum, not movement into it. If Latin wanted to emphasize motion into the forum, it would usually use in with the accusative instead.

Because it is the direct object of videmus.

In the sentence, we see what?
Answer: the cup.

That makes poculum the direct object, so it appears in the accusative singular.

A useful thing to notice is that poculum is a neuter noun, and in the singular its nominative and accusative forms are often the same. So here poculum could look like a subject form to an English speaker, but in this sentence it is functioning as the object.

The verb tells you. Videmus means we see.

The ending -mus shows first person plural, so the subject is we. Latin often leaves the subject pronoun unstated because the verb ending already gives that information.

So Latin does not need to say nos videmus unless it wants extra emphasis on we.

Ex is a preposition that takes the ablative, and one of its common meanings is out of, from, or made of.

• argentum = silver
• argento = ablative singular
• ex argento = from silver or more naturally made of silver

So this phrase describes the material of the cup.

Latin often expresses material with a prepositional phrase such as ex + ablative.

So where English says a silver cup, Latin can say poculum ex argento, literally a cup out of silver or a cup made of silver.

Latin can also sometimes use adjectives for material, but ex + ablative is a very common and straightforward way to express what something is made from.

Latin word order is much more flexible than English word order because Latin uses case endings to show how words function.

English relies heavily on position:

• we see the cup is different from the cup sees us

Latin can move words around more freely because forms like foro and argento show ablative, and videmus clearly shows we see.

So In foro poculum ex argento videmus is perfectly normal Latin. A more English-like order might be:

• Videmus poculum ex argento in foro

But the original sentence is still easy for a Latin reader to understand.

Yes, possibly. Latin often places a word or phrase early in the sentence to set the scene or give it slight emphasis.

Starting with in foro immediately tells you the location: in the forum. It is a natural way to frame the sentence before introducing what is seen.

So the order may feel a bit like:

• In the forum, we see a cup made of silver.

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

So poculum can mean:

• a cup
• the cup

Which one is best depends on context. If the meaning has already been provided to the learner, that meaning is coming from context or from the teaching translation, not from a separate Latin article.

In this sentence, it most naturally describes poculum.

That is because:

• semantically, a cup can be made of silver
• ex argento is placed right after poculum
• there is no other nearby noun that makes better sense with it

So the phrase is understood as a cup made of silver.

You would usually look them up like this:

• in = preposition meaning in, on, into
• forum, fori = forum, marketplace
• poculum, poculi = cup, drinking vessel
• ex = preposition meaning out of, from
• argentum, argenti = silver
• video, videre, vidi, visum = see

From that last entry, videmus is recognized as a form of video.

Yes. The English word forum comes directly from Latin forum.

In Roman context, a forum was a public space used for business, politics, and social activity. So in Latin, in foro means being in that public square or marketplace area.

A classroom pronunciation in reconstructed Classical Latin would be approximately:

in FO-ro PO-ku-lum eks ar-GEN-to wi-DE-mus

A few helpful points:

• v is pronounced like English w in Classical pronunciation, so videmus sounds like widemus
• c is always hard, so poculum has the k sound
• g is always hard, so argento has a hard g

If someone is using an ecclesiastical pronunciation, some sounds would differ, but the grammar stays the same.