Soror digitum matri ostendit et bracchium lavat.

Because soror is in the nominative singular, the case normally used for the subject.

In this sentence:

• soror = subject, sister
• ostendit = shows
• lavat = washes

So soror is the one doing both actions.

A useful thing to notice is that Latin often tells you a word’s job by its ending, not mainly by word order.

Because matri is the dative singular of mater.

With ostendere (to show), Latin commonly uses:

• the thing shown in the accusative
• the person shown to in the dative

So:

• digitum = the thing being shown
• matri = to the mother

English uses to here, but Latin usually just changes the noun ending instead.

They are both direct objects, so they are in the accusative singular.

• digitum is the accusative singular of digitus (finger)
• bracchium is the accusative singular of bracchium (arm)

They answer the question what?

• ostendit what? → digitum
• lavat what? → bracchium

So both are objects of the verbs.

Because bracchium is a neuter noun of the second declension, and in neuter nouns the nominative and accusative singular are the same.

So:

• nominative singular: bracchium
• accusative singular: bracchium

Even though the form looks unchanged, its role in this sentence is still accusative, because it is the object of lavat.

Yes. In this sentence, et simply joins the two actions:

• ostendit
• lavat

Since no new subject is introduced, the subject remains soror for both verbs.

So the structure is basically:

• The sister shows...
• and washes...

Latin often avoids repeating the subject when it stays the same.

Here they are understood as present tense:

• ostendit = shows
• lavat = washes

Both are third person singular, because the subject is one person: soror.

One small point: ostendit can sometimes also be a perfect form (showed / has shown) in other contexts. But here, because it is paired with lavat and because of the intended meaning, it is understood as present.

Because Latin has no articles.

So Latin simply says:

• soror
• digitum
• matri
• bracchium

Depending on context, these could be understood in English with a, the, or sometimes no article at all.

That means the learner has to get used to Latin not marking that distinction directly.

Strictly speaking, the sentence itself does not say.

There is no possessive word like:

• suum / suam = his/her own
• eius = his/her

So from grammar alone, digitum and bracchium just mean the finger and the arm.

In many simple Latin teaching sentences, readers naturally assume these body parts belong to the main person in the sentence, but that is really a matter of context, not something explicitly stated here.

Yes. Latin word order is more flexible than English because the noun endings show each word’s function.

For example, these would still express the same basic idea:

• Soror matri digitum ostendit et bracchium lavat.
• Digitum soror matri ostendit et bracchium lavat.

The exact word order can change emphasis or style, but the cases still tell you:

• soror = subject
• digitum and bracchium = direct objects
• matri = indirect object

So in Latin, endings matter more than position.

Because Latin usually does not need to.

The verb ending already tells you the person and number:

• lavat = he/she/it washes

Since soror has already been named as the subject, Latin does not need to add ea (she). Repeating it would usually be unnecessary unless the writer wanted extra emphasis or contrast.

That is very normal in Latin: once the subject is clear, it is often left unstated.

The verb ostendere often works with this pattern:

someone + something in the accusative + someone in the dative + verb

So here:

• soror = someone doing the action
• digitum = something shown
• matri = person receiving the showing
• ostendit = shows

This is a very common Latin pattern and worth remembering, because many verbs involving giving, telling, showing, and similar ideas use an indirect object in the dative.