Soror rosam rubram et violam albam in aqua ponit, quia odor earum suavis est.

Soror is a third-declension noun, not a first-declension noun.

Even though many Latin nouns referring to female people end in -a—like puella (girl)—that is not true of all of them. Soror is simply the normal nominative singular form for sister.

Its basic forms are:

• soror = sister
• sororis = of the sister

So in this sentence, soror is the subject: the sister.

They are in the accusative singular because they are the direct objects of ponit.

The verb ponere means to place / put. The thing being placed goes into the accusative:

• rosam = a rose / the rose
• violam = a violet / the violet

So the sister is placing the red rose and the white violet.

Because adjectives must agree with the nouns they describe in:

• gender
• number
• case

So:

• rosam rubram = red rose
• violam albam = white violet

Both rosa and viola are feminine singular accusative here, so their adjectives must also be feminine singular accusative:

• rubra → rubram
• alba → albam

Because in can take either the ablative or the accusative, depending on the meaning.

• in + ablative = in/on a place, showing location
• in + accusative = into/onto a place, showing motion toward

Here we have:

• in aqua = in the water

This suggests the flowers are being placed in the water as a location.

A learner might expect into the water, which in Latin would more naturally be:

• in aquam

But Latin sometimes uses in + ablative in ways that are a little broader than a beginner may first expect. Still, the main rule to remember is:

• aqua = ablative singular
• therefore in aqua is a location expression

Ponit is:

• third person singular
• present tense
• active voice
• from ponere = to put / place

So it means:

• she puts
• she is putting
• sometimes simply puts

Because the subject is soror (sister), we understand the subject of ponit as she.

Latin word order is much freer than English word order because Latin uses endings to show grammatical function.

So:

• Soror rosam rubram et violam albam in aqua ponit
• literally: Sister the red rose and the white violet in water places

This is normal Latin style. Very often the verb comes at or near the end, though it does not have to.

English depends much more on word order, but Latin depends much more on case endings.

Quia means because.

It introduces a clause giving the reason:

• quia odor earum suavis est
• because their scent is sweet

So the sentence has:

1. a main clause: Soror ... ponit
2. a reason clause: quia ... est

Because odor is the subject of the clause quia odor earum suavis est.

That clause means:

• the scent of them is sweet

Since odor is the thing that is sweet, it must be in the nominative singular:

• odor = scent / smell
• odorem would be accusative, which would not fit here

Because earum is the genitive plural feminine form of the pronoun is, ea, id.

It refers back to:

• rosam and violam

Both of those nouns are feminine, so Latin uses the feminine plural form:

• earum = of them / their for feminine plural nouns
• eorum would be masculine or neuter plural

So:

• odor earum = their scent / more literally the scent of them

Because earum does not agree with odor. It refers to the two flowers.

This is an important point. In:

• odor earum

the word odor is singular because there is one scent being spoken of, or one scent considered collectively.
But earum is plural because it means of them, referring to both the rose and the violet.

So the grammar is:

• odor = the scent
• earum = of them

Together: their scent.

Earum is genitive plural feminine.

The genitive often expresses ideas like:

• of
• possession
• belonging

So:

• odor earum = the scent of them
• idiomatic English: their scent

This is a very common Latin use of the genitive.

Because suavis is describing odor, which is the subject of the clause, not a direct object.

In:

• odor earum suavis est

suavis is a predicate adjective after est. Predicate adjectives agree with the subject:

• odor = nominative singular masculine
• suavis = nominative singular masculine/feminine form

So suavis est means:

• is sweet
• is pleasant-smelling

If suavis were modifying an accusative noun, then a different form might be needed. But here it matches odor as the subject.

Not necessarily. In Latin, odor can mean simply smell, scent, or fragrance. It does not have to be negative.

In this sentence, since the smell is described as suavis (sweet, pleasant), odor clearly means something like:

• scent
• fragrance

rather than a bad smell.

Classical Latin normally has no articles.

So:

• soror can mean sister, a sister, or the sister
• rosam can mean a rose or the rose
• violam can mean a violet or the violet

The exact sense comes from the context.

That is why Latin learners must get used to the fact that Latin often leaves English article choices to the translator.

We know from gender, number, and context.

• earum is feminine plural
• the nearby likely antecedents are rosam and violam
• both are feminine singular nouns joined by et, so together they make a feminine plural idea

So earum naturally refers to the rose and the violet.

Yes, but that would mean something slightly different:

• odor earum = their scent as a single combined fragrance, or scent viewed collectively
• odores earum = their scents, treating each flower’s smell separately

Latin here uses the singular odor, which is very natural if the speaker is thinking of the flowers’ fragrance as one pleasant smell.

Yes. Latin commonly places an adjective either after or before its noun, but here each adjective follows its noun:

• rosam rubram
• violam albam

This makes the pairings very clear:

• rose — red
• violet — white

Because Latin uses agreement in gender, number, and case, it is easy to see which adjective belongs with which noun.

It breaks down like this:

Main clause

• Soror = subject
• rosam rubram et violam albam = direct objects
• in aqua = prepositional phrase
• ponit = verb

Subordinate clause

• quia = because
• odor = subject
• earum = genitive, of them / their
• suavis = predicate adjective
• est = is

So the pattern is:

• The sister places the red rose and the white violet in water, because their scent is sweet.