Calx puellae post longam viam rubet.

Because calx is in the nominative singular, which is the normal case for the subject.

Also, the verb rubet is third person singular, so it needs a singular subject. Calx fits that perfectly.

By contrast, puellae is not nominative singular. The nominative singular of puella would be puella, not puellae.

Here puellae is genitive singular and means of the girl.

So calx puellae means the girl’s heel or more literally the heel of the girl.

The ending -ae can also be dative singular in other contexts, but here the genitive makes sense because it shows possession.

Latin often shows possession with the genitive case rather than with a separate possessive word.

So instead of saying her heel, Latin can simply say calx puellae, literally the heel of the girl.

Latin could use eius for her, but it does not need to here.

Because post takes the accusative case when it means after.

So:

• post = after
• viam = accusative singular of via

That is why you get post longam viam.

Because longam is an adjective modifying viam, and Latin adjectives must agree with the nouns they describe in:

• gender
• number
• case

Since viam is feminine singular accusative, longam must also be feminine singular accusative.

Rubet is:

• third person singular
• present tense
• active
• indicative

It comes from rubeo, rubere, meaning to be red, to grow red, or to redden.

So rubet can mean is red or has turned red, depending on context.

Yes, here calx means heel.

Like many Latin words, calx can have more than one meaning in different contexts, including meanings related to lime or chalk. But in this sentence, with puellae and rubet, the body-part meaning heel is clearly the right one.

Because Latin has no definite article and no indefinite article.

That means Latin does not have separate words for the, a, or an. Whether English uses the or a depends on the context and on what sounds natural in translation.

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

In English, word order does much of that work. In Latin, the endings already tell you who is doing what, so the writer has more flexibility.

This sentence puts the verb rubet at the end, which is very common in Latin. The order also lets calx come first for emphasis.

A different order such as Puellae calx post longam viam rubet would still mean basically the same thing.

Very literally, yes, since via often means road, way, or path.

But in context, English may use a more natural expression such as after a long walk or after a long journey. Latin often allows a word like via to cover several related ideas, and the best English wording depends on context.

You would normally look them up as follows:

• calx, calcis = heel
• puella, puellae = girl
• post = after
• longus, longa, longum = long
• via, viae = road, way
• rubeo, rubere = be red, grow red

This is especially useful for words like calx, because the nominative calx does not show the stem as clearly as the genitive calcis does.