Pietas filiae clara est, cum aviam aegrotam quiete curat.

Because filiae is in the genitive singular form of filia, meaning daughter.

So:

• filia = daughter
• filiae = of the daughter

In this sentence, filiae depends on pietas:

• pietas filiae = the devotion/dutifulness of the daughter or the daughter’s devotion

A learner might notice that filiae could also be dative singular in other contexts, but here the meaning and sentence structure show that it is genitive.

Pietas is an important Latin word that is broader than English piety in the narrow religious sense.

Here it means something like:

• devotion
• dutiful love
• family loyalty
• sense of responsibility

In Roman culture, pietas often refers to proper devotion toward:

• family
• the gods
• one’s country

So in this sentence, pietas filiae suggests the daughter’s loving and dutiful care for her grandmother.

Because clara agrees with pietas, which is a feminine singular noun.

Latin adjectives must agree with the noun they describe in:

• gender
• number
• case

So:

• pietas = feminine singular
• clara = feminine singular nominative

That is why Latin uses clara est = is clear/evident.

Because the sentence is not saying the daughter is clear. It is saying the daughter’s devotion is clear.

Compare:

• filia clara est = the daughter is famous/clear/bright depending on context
• pietas filiae clara est = the daughter’s devotion is clear

So the main subject is pietas, not filia.

Here cum means when.

It introduces a subordinate clause:

• cum aviam aegrotam quiete curat = when she quietly cares for her sick grandmother

Latin cum can have several meanings, such as:

• when
• since
• although

The exact meaning depends on context and on the verb form used in the clause. In this sentence, with curat in the indicative, when is the most natural understanding.

Curat is the third person singular present active indicative of curare, meaning to care for.

It means:

• she cares for
• he cares for
• it cares for

Here it means she cares for, referring to the daughter.

The present tense can describe:

• an action happening now
• a habitual action
• a general truth

In this sentence, it can sound like a general statement: the daughter’s devotion is evident when she cares for her sick grandmother.

Latin often leaves subject pronouns unstated because the verb ending already shows the person and number.

• curat = she/he/it cares for

Since the context points to the daughter, we understand:

• cum aviam aegrotam quiete curat = when she quietly cares for her sick grandmother

So Latin does not need to add ea for she unless it wants extra emphasis or contrast.

Because aegrotam is an adjective describing aviam, and adjectives must agree with the nouns they modify.

Here:

• aviam = accusative singular of avia (grandmother)
• aegrotam = accusative singular feminine of aegrotus (sick)

Together they mean:

• aviam aegrotam = her sick grandmother

They are both accusative because aviam is the direct object of curat, and the adjective must match it.

Latin does not always form adverbs the same way English does. Here quiete is an adverbial use of the ablative, meaning something like:

• quietly
• calmly
• gently

So:

• quiete curat = she cares for her quietly / she cares for her in a calm way

A native English speaker may expect a separate adverb form, but Latin often uses either:

• a regular adverb, or
• an ablative form used adverbially

Here quiete expresses manner.

Latin word order is much more flexible than English word order because Latin uses case endings to show grammatical relationships.

English depends heavily on position:

• The daughter cares for the grandmother

Latin can move words around more freely because forms like aviam and filiae already show their roles.

So in this sentence:

• Pietas filiae clara est, cum aviam aegrotam quiete curat

the order is natural Latin, even though English would usually arrange it more rigidly.

Latin often places the verb later in the clause, and it can place important words in prominent positions for emphasis.

Not grammatically, because filiae is genitive here, not nominative.

The subject of curat is understood, not expressed. It is she, referring in sense to the daughter. So the idea is:

• The daughter’s devotion is clear, when she cares for her sick grandmother.

Even though filiae is not the grammatical subject of curat, it helps us understand who she is.

Latin has no definite or indefinite articles, so it does not have exact equivalents of English the or a/an.

That means:

• filiae can mean of the daughter or of a daughter
• aviam can mean grandmother or the grandmother
• in context, English usually supplies the most natural article

Also, Latin often leaves possessive ideas unstated when they are obvious from context. So aviam may naturally be understood as her grandmother, even though Latin does not explicitly say suam aviam here.

Yes. Latin cum clauses often use the subjunctive, especially when they are:

• causal (since)
• concessive (although)
• circumstantial in a more literary style

But in this sentence we have:

• cum ... curat

with the indicative curat, which suits a straightforward temporal meaning: when.

So a learner should notice that cum does not always behave the same way; the verb mood helps show the type of clause.