Crusta nucleo adhaeret; coagmentum tenue manet.

The subjects are crusta and coagmentum.

Why?

• Crusta is in the nominative singular, which is the normal case for the subject of adhaeret.
• Coagmentum is also in the nominative singular, matching manet.
• Both verbs are 3rd person singular, so each clause needs a singular subject.

So the structure is:

• Crusta nucleo adhaeret = crusta is the subject
• coagmentum tenue manet = coagmentum is the subject

Because adhaereo commonly takes the dative case.

So:

• nucleo = to the kernel
• adhaeret = clings / adheres

A very literal gloss would be:

• Crusta nucleo adhaeret = The crust adheres to the kernel

This is a common thing for English speakers to notice, because English uses to before the object here, while Latin often uses the dative without a preposition after certain verbs.

Here are the main dictionary forms:

• crusta, -ae, f. = crust, shell, rind
• nucleus, -i, m. = kernel, core
• adhaereo, adhaerere, adhaesi, adhaesum = cling to, adhere to
• coagmentum, -i, n. = joining, bond, seam, compacted mass
• tenuis, tenue = thin, slender, slight
• maneo, manere, mansi, mansum = remain, stay

For a learner, it is especially useful to notice:

• nucleus becomes nucleo in the dative singular
• tenuis has the neuter nominative singular form tenue

Because tenue agrees with coagmentum, and coagmentum is neuter singular.

The adjective tenuis, tenue is a third-declension adjective:

• masculine/feminine nominative singular: tenuis
• neuter nominative singular: tenue

So:

• coagmentum tenue = thin coagmentum / thin bond / thin seam

If the noun were masculine or feminine singular, you would expect tenuis instead.

A learner could reasonably wonder about that, because Latin allows both kinds of expression.

Grammatically, tenue could be understood in either of these ways:

• attributive: the thin bond remains
• predicative with manet: the bond remains thin

Since you said the meaning is already provided to the learner, that given meaning should decide which reading is intended in this context.

So the main point to learn is: with a verb like manet, a nominative adjective can sometimes feel a bit ambiguous unless the context makes it clear.

Both are present indicative active, 3rd person singular.

• adhaeret = he/she/it adheres
• manet = he/she/it remains

In this sentence, the subjects are things, so in natural English we translate them with it:

• the crust adheres
• the bond remains

The -t ending is the normal sign of 3rd person singular in the present tense.

Because Latin has no articles.

So a word like crusta can mean:

• a crust
• the crust

and coagmentum can mean:

• a bond
• the bond

Context tells you which is best in English. That is why translation into English must often add the or a, even though Latin does not explicitly say them.

The word order is fairly normal, but Latin is much more flexible than English because the endings show each word’s function.

Here we have:

• Crusta nucleo adhaeret
• coagmentum tenue manet

This is broadly:

• subject + complement + verb
• subject + adjective + verb

Latin could rearrange these words without completely changing the basic meaning, for example:

• Nucleo crusta adhaeret
• Tenue coagmentum manet

But different orders can change emphasis or style. English relies heavily on word order; Latin relies much more on inflection.

The semicolon simply separates two closely related independent clauses.

So the sentence gives two linked statements:

• Crusta nucleo adhaeret
• coagmentum tenue manet

Latin often does this without adding a conjunction such as et. This is a normal stylistic feature. English can do something similar too, especially in more formal writing.

So the semicolon here signals:

• the clauses are separate
• but they belong together in sense

Maneo often means remain, stay, or continue to be.

So manet can be translated in several close ways depending on context:

• remains
• stays
• continues

In this sentence, remains is usually the most natural English choice, because it suggests that something is still in that state after other changes or observations.

That is why coagmentum tenue manet naturally gives the idea of something continuing in its condition.

No. Latin normally does not need an explicit subject pronoun when the verb ending already shows the person and number.

Here:

• adhaeret already means it adheres
• manet already means it remains

And since the nouns crusta and coagmentum are already present, adding a pronoun would be unnecessary.

This is very different from English, where you usually must say it adheres or it remains.