Cum puella ad diversorium sero venisset, hospita ei cenaculum quietum monstravit.

Here cum means when. It introduces a subordinate clause: Cum puella ad diversorium sero venisset = when the girl had arrived late at the inn.

In Latin, cum can mean different things depending on context, such as when, since, or although. In this sentence, it is a temporal/circumstantial cum clause.

Because after cum, Latin often uses the subjunctive when the clause gives the circumstances/background of the main action, not just a simple time statement.

So the sentence is not merely saying at the moment when she arrived. It is giving the setting: when / since / under the circumstances that the girl had arrived late, the hostess showed her a quiet room.

This is a very common Latin pattern:

• cum
  • subjunctive = background, circumstance, cause, or concession

Venisset is:

• 3rd person singular
• pluperfect
• subjunctive
• active of venire = to come

So it means she had come or she had arrived.

The subject is puella, so venisset means the girl had arrived.

The pluperfect shows that this action happened before the action of the main verb.

• venisset = had arrived
• monstravit = showed

So the sequence is:

1. the girl arrived late at the inn
2. the hostess showed her a quiet room

Latin uses the pluperfect here for the same reason English uses had arrived.

Puella is nominative because it is the subject of venisset.

Even though it comes after cum, it is still the subject of the subordinate clause:

• puella ... venisset = the girl had arrived

English speakers sometimes expect a different case after a conjunction, but conjunctions like cum do not determine case. The verb does, and here puella is the one performing the action.

Because ad takes the accusative when it means to or toward a place.

So:

• ad = to, toward
• diversorium = accusative singular

Together:

• ad diversorium = to the inn / hotel / lodging place

This is the normal way to express motion toward something in Latin.

Diversorium means a lodging place, inn, hostel, or sometimes hotel, depending on context.

It is a neuter noun. In this sentence it is singular and accusative because it follows ad.

So ad diversorium means to the inn or to the hotel.

Sero is an adverb meaning late.

It modifies venisset:

• sero venisset = had arrived late

English speakers sometimes look for an adjective ending here, but sero is not describing a noun. It is describing how / when she arrived, so it is an adverb.

Hospita is the subject of the main verb monstravit.

It is:

• nominative singular
• feminine

It means hostess, female host, or in this context probably the innkeeper or woman in charge of the lodging.

So:

• hospita monstravit = the hostess showed

Ei means to her. It is dative singular.

It is used because monstrare can take:

• a direct object = the thing shown
• an indirect object = the person to whom it is shown

So here:

• cenaculum quietum = the thing shown
• ei = the person to whom it was shown

That is why Latin uses ei (to her) rather than eam (her, as a direct object).

Cenaculum quietum means a quiet room or a quiet upstairs room/chamber.

Both words are accusative singular neuter because:

• cenaculum is the direct object of monstravit
• quietum is an adjective agreeing with cenaculum

Agreement means the adjective matches the noun in:

• gender
• number
• case

So:

• cenaculum = neuter singular accusative
• quietum = neuter singular accusative

Monstravit is:

• 3rd person singular
• perfect
• active
• indicative of monstrare = to show

So it means she showed.

The subject is hospita, so:

• hospita monstravit = the hostess showed

Latin word order is much more flexible than English word order because Latin shows grammatical relationships through endings, not mainly through position.

A very literal order here would be:

• When the girl to the inn late had-arrived, the hostess to-her a quiet room showed.

That sounds strange in English, but it is normal Latin style. A few things are especially common:

• the subordinate clause often comes first
• the verb often comes at or near the end of its clause
• important words can be placed for emphasis

So the word order is natural Latin, even though it is not natural English.

No. Cum can take either the indicative or the subjunctive, depending on the meaning.

Very broadly:

• cum + indicative often gives a more straightforward when
• cum + subjunctive often gives background, cause, or concession

In this sentence, the subjunctive fits the narrative style: it sets the scene for the main action.

The sentence has two parts:

1. Cum puella ad diversorium sero venisset

   • subordinate cum clause
   • gives the background: when the girl had arrived late at the inn

2. hospita ei cenaculum quietum monstravit

   • main clause
   • tells the main event: the hostess showed her a quiet room

So the whole sentence is structured as:

• background first
• main action second

That is a very common pattern in Latin narrative.