Si nihil in crumena est, a mercatore nihil emere possumus.

Si introduces a condition: if.

So the first part, Si nihil in crumena est, sets up the condition, and the second part tells what follows from it. This is a very normal, straightforward Latin if-sentence, using the present tense in both clauses.

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

So crumena can mean a purse or the purse, and mercatore can mean a merchant or the merchant, depending on context. English has to add an article, but Latin usually leaves that unstated.

Because it is doing two different jobs in the sentence.

• In Si nihil in crumena est, nihil means nothing and is the subject of est: nothing is in the purse.
• In a mercatore nihil emere possumus, nihil is the object of emere: we can buy nothing.

So Latin is not being redundant in a strange way; it is simply saying nothing in both clauses for two separate ideas.

Also, nihil has the same form for both nominative and accusative, so it looks the same in both places.

Because in takes different cases depending on the meaning:

• in + ablative = in/on a place, with no movement
• in + accusative = into/onto a place, with movement toward it

Here the meaning is location: in the purse, not into the purse. So Latin uses the ablative: in crumena.

If the sentence meant something like he puts the money into the purse, then you would expect in crumenam.

A mercatore means from the merchant.

The preposition is a/ab, meaning from or sometimes by. It takes the ablative case, so mercatore is ablative singular.

A useful detail:

• a is commonly used before a consonant
• ab is commonly used before a vowel or h

Since mercatore begins with m, a mercatore is the expected form.

In this sentence, it shows the source of the buying: from a merchant.

Because it depends on possumus.

Latin uses possum + infinitive to mean can / am able to do something.

So:

• possumus = we are able
• emere = to buy
• emere possumus = we are able to buy / we can buy

This is very similar to English can buy, except Latin expresses the second verb as an infinitive.

The ending -mus tells you the subject is we.

Latin verb endings often include the subject, so a separate word for we is not necessary.
So possumus by itself already means we can or we are able.

If Latin wanted extra emphasis, it could say nos possumus, but usually possumus alone is enough.

Because Latin word order is much more flexible than English word order.

Latin often puts the verb near the end of the clause, especially in simple prose. That is why we get:

• nihil in crumena est
• nihil emere possumus

English usually prefers a more fixed order, but Latin relies much more on word endings to show each word's role.

So the sentence could be rearranged in other ways without changing the basic meaning, although some orders sound more natural than others.

No. Even though it looks the same, it is completely different.

• English a is an article.
• Latin a is a preposition meaning from or by.

So in a mercatore, the a does not mean a merchant. It is part of the phrase from the merchant.