Lucia unum vocabulum novi auctoris non intellegit, sed post lectionem sensum eius invenit.

Because Latin verbs already show person and number, intellegit by itself means he/she/it understands. The name Lucia is added to make the subject explicit: it tells you exactly who she is. Latin often includes the subject noun for clarity, contrast, or emphasis, even though it is not strictly necessary.

In this sentence, Lucia is nominative singular, the subject of both intellegit and invenit.

Because vocabulum is neuter singular, and unus must agree with it in gender, number, and case.

• vocabulum = neuter singular accusative here
• so one must also be neuter singular accusative
• that form is unum

So unum vocabulum means one word and functions as the direct object of non intellegit.

It is accusative singular. You know this because it is the direct object of intellegit: it is the thing Lucia does not understand.

The phrase is:

• unum vocabulum = one word

Both words are accusative singular, and together they form the object of the verb.

Because it depends on vocabulum and means of the new author.

So the structure is:

• unum vocabulum = one word
• novi auctoris = of the new author

This is a genitive phrase showing possession or association: one word of the new author.

Also notice the agreement:

• auctoris is genitive singular
• novi is also genitive singular masculine, agreeing with auctoris

If novus were describing vocabulum, it would have to be novum, not novi.

Either is possible grammatically. Latin has no definite or indefinite article, so it does not have separate words for the and a/an.

That means:

• novi auctoris can mean of the new author
• or of a new author

Context or the given translation tells you which English version fits best.

Intellegit is 3rd person singular present active indicative of intellegere.

So it means:

• he understands
• she understands
• it understands

With non, it becomes does not understand.

Because the subject is Lucia, here it means Lucia does not understand.

That is the normal way to negate a verb in Latin. Non usually comes right before the word or phrase it negates, and very often that is the finite verb.

So:

• intellegit = understands
• non intellegit = does not understand

Because post is a preposition that takes the accusative case.

So:

• lectio, lectionis = reading, a reading, lesson
• accusative singular = lectionem
• post lectionem = after the reading or after reading

This is just a standard prepositional construction: post + accusative.

Yes. Literally it is after the reading, but English often prefers a smoother expression like after reading.

Latin frequently uses a noun where English might use:

• a gerund: after reading
• or a clause: after she reads

So post lectionem is a perfectly natural Latin way to express that idea.

Sensum is accusative singular, and it is the direct object of invenit.

So in the second half of the sentence:

• sensum eius = its meaning / its sense
• invenit = finds or found

Lucia is finding the meaning, so sensum has to be in the accusative.

Also, sensus is a 4th-declension noun, so its accusative singular is sensum.

It refers to vocabulum. So sensum eius means its meaning, that is, the meaning of the word.

The idea is:

• first, Lucia does not understand the word
• later, she finds the meaning of that word

So eius points back to vocabulum.

Because eius is the genitive singular form used for of him, of her, or of it. The same form works for all three genders in the singular.

So even though vocabulum is neuter, eius is still correct for of it.

This can feel strange to English speakers because it does not visibly look neuter, but in Latin it is normal.

Because suus, sua, suum usually refers back to the subject and means his/her/its own.

Here the meaning belongs to the word, not to Lucia. So Latin uses eius = of it.

Compare the difference:

• sensum eius = its meaning (the meaning of the word)
• sensum suum would more naturally suggest her own meaning or something referring back to Lucia

So eius is the right choice.

In ordinary spelling, invenit can be ambiguous:

• present: finds
• perfect: found

With macrons, the perfect is written invēnit, which helps distinguish it.

So how do you know which one is meant? You use context or the given translation. If the sentence is being read as present-time narrative, then it is finds. If the translation given to the learner is past, then it is found.

This is a very common kind of ambiguity in Latin when macrons are not shown.

Because Latin word order is much more flexible than English word order. Latin relies heavily on case endings, so it does not need a strict subject-verb-object order.

A verb often comes late, especially in a fairly neutral or literary sentence. Here that gives a neat structure:

• Lucia unum vocabulum novi auctoris non intellegit
• sed post lectionem sensum eius invenit

The important objects and modifiers come first, and the verbs complete each clause at the end.

Usually yes, but it can also carry a slight emphasis like a single word or one particular word, depending on context.

So a learner should understand that unum is not just counting mechanically. It can also highlight that only one word is causing trouble.