Faber unam trabem mutat et duas columnas purgat antequam pluvia redeat.

Faber is in the nominative singular, which is the usual case for the subject of a finite verb. Also, both mutat and purgat are third person singular verbs, so they match a singular subject: faber.

In other words:

• faber = subject
• mutat = he changes
• purgat = he cleans

Latin often puts the subject first, but it does not have to.

They are direct objects, so they are in the accusative case.

Here is the pattern:

• unam trabem = one beam as the thing being changed
• duas columnas = two columns as the things being cleaned

The verbs are acting on those nouns:

• mutat what? unam trabem
• purgat what? duas columnas

That is why those noun phrases are accusative rather than nominative.

Because trabs is not in the nominative here. It is the direct object, so it has to be accusative singular.

The dictionary form is:

• trabs, trabis = beam

This is a third-declension feminine noun. Its accusative singular is trabem.

The numeral one also has to agree with the noun in gender, number, and case, so:

• feminine
• singular
• accusative

gives unam.

So:

• nominative: una trabs
• accusative: unam trabem

Because duo declines and changes form. It must agree with columnas in gender, number, and case.

columna is feminine, and here it is accusative plural:

• nominative plural feminine: duae
• accusative plural feminine: duas

So duas columnas is the correct form for two columns as a direct object.

Yes. In this sentence, unam and duas are numerals, but they behave very much like adjectives because they agree with the nouns they modify.

They match their nouns in:

• gender
• number
• case

So:

• unam trabem: feminine, singular, accusative
• duas columnas: feminine, plural, accusative

That agreement is a very important feature of Latin.

Because one subject can govern more than one verb. Here faber is the subject of both mutat and purgat.

So the structure is basically:

• Faber mutat
• et faber purgat

But Latin does not need to repeat faber, because it is understood. English does the same thing:

• The craftsman changes one beam and cleans two columns

We do not normally repeat the craftsman before cleans either.

Antequam means before and introduces a subordinate clause.

So the sentence has:

• a main clause: Faber unam trabem mutat et duas columnas purgat
• a subordinate clause: antequam pluvia redeat

That subordinate clause tells us before what event the action of the main clause happens.

This is one of the most common questions in Latin.

After antequam, Latin often uses the subjunctive when the action in the subordinate clause is viewed as anticipated, intended, or still in the future relative to the main action.

So antequam pluvia redeat means something like:

• before the rain returns
• with the sense of an expected future event

Redeat is the present subjunctive of redeo.

A simple way to think about it is:

• redit = returns as a straightforward fact
• redeat = may return / is to return / returns in a subordinate clause with a more prospective or anticipated sense

In beginner reading, it is often enough to remember: antequam + subjunctive is very common when the action has not yet happened from the point of view of the main clause.

Pluvia is nominative singular, and it is the subject of redeat.

So in the subordinate clause:

• pluvia = subject
• redeat = verb

That is why pluvia is not accusative. It is not something being acted upon; it is the thing that returns.

They are both present active indicative, third person singular.

So:

• mutat = he/she/it changes
• purgat = he/she/it cleans

Since the subject is faber, they mean:

• the craftsman changes
• the craftsman cleans

The present tense in Latin can be used much like the English present, depending on context.

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

This sentence could be rearranged in various ways without changing the basic meaning, for example:

• Unam trabem faber mutat et duas columnas purgat antequam pluvia redeat
• Faber antequam pluvia redeat unam trabem mutat et duas columnas purgat

However, the original order is perfectly natural. It presents:

1. the subject
2. the first object and verb
3. the second object and verb
4. the time clause at the end

Word order in Latin often affects emphasis more than basic grammatical function.

A learner often wants to identify the vocabulary behind the forms. Here are the basic forms:

• faber, fabri = craftsman, workman
• unus, una, unum = one
• trabs, trabis = beam
• muto, mutare = change
• duo, duae, duo = two
• columna, columnae = column
• purgo, purgare = clean, cleanse
• antequam = before
• pluvia, pluviae = rain
• redeo, redire = return

Knowing the dictionary form helps you understand why the endings look the way they do in the sentence.