Nummularius in foro denarios et sestertios mutat, sed pater queritur eum nimium lucrum quaerere.

Because in with the ablative usually shows location: in the forum / in the marketplace.

• in foro = in the forum
• If in took the accusative, it would usually suggest motion into something.

So here the money-changer is working in the marketplace, not moving into it.

Nummularius means a money-changer, and sometimes more broadly a banker or someone who deals with coins.

It comes from nummus, meaning coin. In this sentence, the idea is that he exchanges one kind of coin for another.

They are the direct objects of mutat.

• mutat = changes / exchanges
• What does he exchange? denarios et sestertios

So both nouns are in the accusative because they are the things being dealt with.

Also:

• denarios = accusative plural of denarius
• sestertios = accusative plural of sestertius

They are Roman coins.

• denarius: a well-known silver coin
• sestertius: another Roman denomination, often used in accounting and prices

A learner does not need all the monetary details to understand the grammar, but it helps to know that the sentence is about exchanging money.

More specifically, here it means exchanges.

In English, change can be vague, but in a money context Latin mutare often means to exchange one thing for another, especially coins or money.

So denarios et sestertios mutat means something like:

• he exchanges denarii and sestertii
• or more naturally, he changes money

Because of the structure of the sentence:

• Nummularius in foro denarios et sestertios mutat
• sed pater queritur eum nimium lucrum quaerere

After sed (but), a new subject appears: pater.

So the sentence shifts from:

• the money-changer ... exchanges coins

to:

• but the father complains ...

Latin often changes subjects this way without needing extra words.

Queritur is a deponent verb.

That means:

• it looks passive in form
• but it has an active meaning

So queritur means he complains or he complains that ..., not he is complained about.

Its dictionary form is queror, queri, questus sum = to complain.

This is the accusative and infinitive construction, often called indirect statement.

After verbs of saying, thinking, perceiving, and sometimes complaining, Latin often uses:

• accusative subject
  • infinitive verb

So:

• pater queritur eum nimium lucrum quaerere

literally means:

• the father complains him to seek too much profit

But in natural English:

• the father complains that he is seeking too much profit

Here:

• eum = the subject of the infinitive quaerere
• quaerere = infinitive, to seek

It refers to nummularius, the money-changer.

So the meaning is:

• the father complains that the money-changer is seeking too much profit

This is a very common point for learners, because Latin uses eum in the accusative as the subject of the infinitive.

Because the subject of the main verb queritur is pater, not nummularius.

In an indirect statement:

• se usually refers back to the subject of the main verb
• eum refers to someone else

So:

• pater queritur eum ... = the father complains that he (the money-changer) ...
• pater queritur se ... = the father complains that he himself (the father) ...

That is an important distinction.

It means too much profit or excessive profit.

• lucrum = profit, gain
• nimium here modifies lucrum

So the father thinks the money-changer is trying to make more profit than is proper.

Here it is best understood as agreeing with lucrum, so effectively as too much modifying the noun:

• nimium lucrum = too much profit

Formally, nimium is neuter singular accusative, matching lucrum, which is also neuter singular accusative.

Learners may notice that nimium can also be used adverbially in other contexts, but in this sentence it naturally goes with lucrum.

Because quaerere means to seek, and lucrum quaerere is an idiomatic way to say:

• to seek profit
• to aim at profit
• to make money / pursue gain

So it does not necessarily mean literal physical searching. It means trying to profit.

Yes, but it is normal Latin word order.

A few points:

• Nummularius comes first, making the topic clear immediately.
• in foro is placed early, giving the setting.
• sed pater clearly marks the contrast.
• eum nimium lucrum quaerere is saved until the end as the content of the complaint.

Latin word order is often more flexible than English word order, but the grammar endings show the relationships clearly.

Sometimes Latin can omit a pronoun if the reference is clear, but here eum is very helpful because it shows clearly who is doing the quaerere.

Without eum, the sentence would be less precise, especially since the subject has just changed to pater. Including eum makes it obvious that the father is complaining about the money-changer, not about himself.

All the finite verbs here are in the present tense:

• mutat = he exchanges
• queritur = he complains

And the infinitive quaerere is a present infinitive, which in indirect statement usually shows action happening at the same time as the main verb:

• pater queritur eum ... quaerere
• the father complains that he is seeking ...

So the whole sentence presents the actions as ongoing or current.