Cortex huius quercus asper est, sed puella eum libenter tangit.

Because cortex is in the nominative singular, which is the case normally used for the subject of a clause.

In Cortex huius quercus asper est:

• cortex = the bark
• asper est = is rough

So literally, the structure is:

• cortex = subject
• asper = predicate adjective
• est = verb

In other words, the bark is what is rough.

Because asper agrees with cortex, and cortex is a masculine noun.

In Latin, an adjective must agree with the noun it describes in:

• gender
• number
• case

So here:

• cortex = masculine singular nominative
• asper = masculine singular nominative

Even though bark is not thought of as masculine in English, Latin uses grammatical gender, not natural gender.

Huius means of this or of this one here.

It is the genitive singular form of hic, haec, hoc (this).

So:

• huius quercus = of this oak

The genitive is often used to show possession or close relationship, so cortex huius quercus means the bark of this oak.

This is a very common point of confusion.

Quercus is a fourth-declension noun, and its nominative singular and genitive singular are written the same way in ordinary spelling:

• nominative singular: quercus
• genitive singular: quercūs

In fully marked texts, the genitive has a long ū, but many beginner texts do not mark vowel length consistently. So in your sentence, huius quercus must be genitive because huius already signals that meaning clearly.

So although it looks unchanged, it means:

• of this oak

It is a genitive phrase modifying cortex.

So:

• cortex = bark
• huius quercus = of this oak

Together:

• cortex huius quercus = the bark of this oak

A good way to think of it is that huius quercus answers the question:

• whose bark?
• the bark of this oak

Eum is the accusative singular masculine form of is, ea, id (he, she, it / him, her, it depending on context).

Here it refers back to cortex.

Since tangit means touches, it needs a direct object in the accusative case:

• puella = subject
• eum = direct object
• tangit = touches

So eum means it, specifically the bark.

Because Latin pronouns agree with the grammatical gender of the noun they refer to, not with whether the thing is alive or male.

Since cortex is masculine, the pronoun referring to it is also masculine:

• cortex → masculine
• eum → masculine accusative singular

In English, we usually say it for objects, but Latin still has to choose masculine, feminine, or neuter according to the noun’s grammatical gender.

Libenter means gladly, willingly, or with pleasure.

It is an adverb, so it modifies the verb tangit:

• puella eum tangit = the girl touches it
• puella eum libenter tangit = the girl gladly touches it

A useful pattern to remember is that Latin often uses adverbs in -ter, and libenter is a very common one.

Latin word order is much more flexible than English word order because case endings show each word’s role.

In this clause:

• puella is nominative, so it is the subject
• eum is accusative, so it is the object
• tangit is the verb

That means Latin can move the words around for emphasis or style without causing much confusion.

The given order feels natural and clear:

• puella = topic/subject first
• eum = object next
• libenter = adverb near the verb
• tangit = verb at the end, which is very common in Latin

Because its subject is puella, which is singular.

Tangit is:

• third person singular
• present tense
• active voice
• indicative mood

So it means she touches or the girl touches.

If the subject were plural, the verb would need to be plural too. For example:

• puellae eum tangunt = the girls touch it

Yes. Sed means but, and it marks a contrast between the two clauses.

The contrast is:

• The bark is rough
• but the girl gladly touches it

That is slightly unexpected, because rough bark might seem unpleasant to touch. So sed highlights that contrast.

Yes, it could, but using eum is very natural.

Latin often uses a pronoun to avoid repeating a noun when the reference is clear. So instead of saying something like:

• sed puella corticem libenter tangit

the sentence uses:

• sed puella eum libenter tangit

That sounds smoother and more natural, just as English often prefers it instead of repeating the bark.

Cortex is a third-declension noun.

Its dictionary form is:

• cortex, corticis = bark

A learner should especially notice that:

• nominative singular = cortex
• accusative singular = corticem

That matters because in this sentence:

• cortex is nominative, as the subject of est
• the second clause does not repeat the accusative corticem, but uses eum instead

So this sentence gives you practice recognizing both:

• the nominative subject cortex
• the pronoun eum standing in for the expected object