Mercator mille nummos numerat.

Mercator is the subject of the sentence, so it is in the nominative singular.

It is a third-declension noun:

• nominative singular: mercator
• genitive singular: mercatoris

A learner may expect the subject to end in -us, because many Latin masculine nouns do, but third-declension nouns often have other nominative endings. So mercator is perfectly normal as a subject form.

Latin has no articles. It does not have separate words for the, a, or an.

So mercator can mean:

• the merchant
• a merchant

Which one sounds best depends on the context. Latin leaves that to the reader or listener to infer.

In this sentence, mille is an indeclinable numeral meaning one thousand. That means its form does not change here.

So:

• mille nummos = a thousand coins

For larger numbers, Latin often uses the plural noun milia:

• duo milia nummorum = two thousand coins

That difference often surprises English speakers:

• mille
  • direct counted noun
• milia
  • a genitive plural noun

So in your sentence, mille is singular in meaning: one thousand.

Because nummos is accusative plural.

The verb numerat takes a direct object: what is the merchant counting? He is counting coins, so nummos is the object.

The noun is nummus, nummi (coin), a second-declension masculine noun. Its accusative plural is nummos.

A quick pattern:

• nominative singular: nummus
• accusative singular: nummum
• nominative plural: nummi
• accusative plural: nummos

So the -os ending tells you these are the things being counted.

Because with mille meaning one thousand, Latin normally puts the counted noun directly in the case required by the sentence.

Here the counted noun is the direct object of numerat, so it appears in the accusative plural:

• mille nummos

By contrast, with milia (thousands), Latin usually uses a genitive plural:

• tria milia nummorum = three thousand coins

So:

• mille nummos
• but duo milia nummorum

That is a very common thing for learners to ask about.

Numerat is:

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

So it means he/she/it counts or is counting, depending on context.

Because the subject is mercator, we understand it as the merchant counts or is counting.

It comes from the verb numero, numerare, numeravi, numeratus.

Latin verbs usually include the subject information in their endings.

The ending -t in numerat means he/she/it. So Latin does not need a separate pronoun here.

That is why numerat by itself can mean:

• he counts
• she counts
• it counts

Since the noun mercator is already present, the subject is clear. Adding is (he) would usually be unnecessary unless you wanted emphasis.

The sentence is perfectly normal as written, but Latin word order is more flexible than English word order because Latin uses case endings to show grammatical roles.

So these all mean roughly the same thing:

• Mercator mille nummos numerat.
• Mille nummos mercator numerat.
• Nummos mille mercator numerat.

The endings tell you:

• mercator = subject
• nummos = object

Even so, word order can affect emphasis. The given order is a straightforward, neutral way to say it.

Yes, depending on context, numero can mean count, reckon, or calculate.

In this sentence, with nummos (coins) as the object, the most natural idea is literal counting:

• the merchant is counting coins

So an English learner should think first of counting out money rather than abstract mathematics.

The noun form mercator here is nominative singular, and the verb numerat is also third person singular.

The verb agrees with its subject:

• singular subject → singular verb
• plural subject → plural verb

If the subject were plural, you would expect something like:

• mercatores mille nummos numerant
• the merchants count a thousand coins

So both the noun and the verb show that the subject is one merchant.

They are usually given like this:

• mercator, mercatoris — merchant
• mille — a thousand
• nummus, nummi — coin
• numero, numerare — to count

A fuller verb entry would be:

• numero, numerare, numeravi, numeratus

Learning the dictionary forms helps you identify:

• the declension of nouns
• the conjugation of verbs
• how other forms are built

For example:

• from nummus, nummi, you can understand where nummos comes from
• from numero, numerare, you can understand where numerat comes from