Tessera nucleo adhaeret.

The subject is tessera.

Why:

• tessera is in the nominative singular
• the verb adhaeret is third person singular, so it matches a singular subject

So tessera is the thing doing the action of sticking / adhering.

Because nucleo is not in the nominative case.

It is dative singular of nucleus. With the verb adhaerere (to stick to, cling to, adhere to), Latin normally uses the dative for the thing something sticks to.

So the structure is:

• tessera = the thing that sticks
• nucleo = the thing it sticks to

In English we often use to:

• The tile sticks to the core.

In Latin, that to idea is built into the combination of the verb and the dative case.

Because adhaerere takes the dative, not the direct object.

For nucleus:

• nominative singular: nucleus
• accusative singular: nucleum
• dative singular: nucleo

Since the verb means adhere to rather than simply acting on a direct object, Latin uses:

• nucleo = to the core

not

• nucleum = which would be an accusative direct object, and that would not be the normal construction here

Adhaeret is:

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

It comes from adhaerere.

So it means:

• he/she/it adheres
• he/she/it sticks
• he/she/it is sticking (depending on context)

Because the subject is tessera, we understand it as it sticks / adheres.

Because Latin often expresses meanings through case endings instead of separate helper words.

In English:

• sticks to the core

In Latin:

• adhaeret nucleo

The -o ending in nucleo shows the dative, which gives the sense of to the core.

So the idea of to is not missing; it is carried by the case ending.

Not very, at least not in the same way as in English.

Latin word endings show each word’s job, so the sentence could often be rearranged without changing the basic meaning. For example, these would still mean essentially the same thing:

• Tessera nucleo adhaeret
• Nucleo tessera adhaeret
• Adhaeret tessera nucleo

That said, word order can affect emphasis. The version you were given is a very straightforward order:

• subject
• indirect-object-like dative
• verb

Also, Latin often places the verb at the end, as here.

It can mean different things depending on context.

Common meanings of tessera include:

• a small cube used in a mosaic
• a tile
• a token
• a tablet or small marked piece

So in a sentence like this, the exact English word depends on the context already given to the learner. Grammatically, though, it is still the subject.

They belong to different declensions:

• tessera = first declension
• nucleus = second declension

Their forms here are:

tessera

• nominative singular
• first declension
• probably feminine

nucleo

• dative singular of nucleus
• second declension
• masculine

This is useful because it helps you identify each word’s case and function.

Classical Latin has no articles like English the or a/an.

So:

• tessera can mean a tile or the tile
• nucleo can mean to a core or to the core

The context tells you which English article makes the most sense.

That is very normal in Latin, and learners have to get used to supplying the or a when translating into English.

Yes, depending on the context.

A few natural English renderings are:

• sticks to
• adheres to
• clings to
• is attached to

The Latin form itself is still just present active indicative, but English may choose a more idiomatic expression. If the meaning has already been supplied, the main grammatical point is that the verb describes a present action or state of adherence.

A common classroom-style pronunciation would be roughly:

• TESS-se-ra NOO-kleh-oh ad-HAE-ret

If you want a more classical approximation:

• tessera = TESS-eh-ra
• nucleo = NOO-kleh-o
• adhaeret = ad-HAE-ret

A few notes:

• ae is usually pronounced like the ai in aisle in restored classical pronunciation
• c is always hard, like k
• every written vowel is pronounced

So adhaeret has three syllables: ad-hae-ret.

The ending -t in adhaeret means third person singular, but by itself it does not tell you whether the subject is he, she, or it.

You find that out from the subject noun:

• tessera is a thing, so in English we usually say it

Latin verbs do not need an expressed pronoun like it, because the verb ending already tells you the person and number:

• adhaeret = he/she/it adheres

Then the noun tessera tells you exactly who or what that he/she/it is.