Hospes in atrium ingressus dominam salutat.

The core of the sentence is:

• Hospes ... salutat = The guest greets
• dominam = the mistress/lady (direct object)
• in atrium ingressus = having entered into the atrium

So the full structure is:

• Hospes — subject
• dominam — direct object
• salutat — main verb
• ingressus — a participle describing hospes
• in atrium — phrase connected with ingressus

A very literal unpacking would be:

The guest, having entered into the atrium, greets the mistress.

Or more naturally in English:

After entering the atrium, the guest greets the mistress.

Hospes is in the nominative singular, which is the case normally used for the subject of a sentence.

Also, ingressus agrees with it:

• hospes = nominative singular
• ingressus = nominative singular masculine

And the main verb salutat is third person singular, matching a singular subject:

• salutat = he/she greets

So grammatically, hospes is the one doing both actions:

• entering
• greeting

Dominam is accusative singular.

It is accusative because it is the direct object of salutat:

• salutat aliquem = greets someone

So:

• hospes = the one doing the greeting
• dominam = the person being greeted

The base noun is domina (lady, mistress of the house), and its accusative singular form is dominam.

Because Latin uses in + accusative for motion into something, and in + ablative for location in something.

Here the sentence involves movement:

• ingressus = having entered
• so the guest moves into the atrium

Therefore:

• in atrium = into the atrium

Compare:

• in atrium = into the atrium
• in atrio = in the atrium

This is a very common distinction in Latin.

Ingressus is the perfect participle of the verb ingredior, ingredi, ingressus sum, meaning enter or go into.

In this sentence it means:

• having entered
• after entering

It is a participle, so it behaves partly like a verb and partly like an adjective:

• like a verb, it can take complements such as in atrium
• like an adjective, it agrees with hospes

So hospes ... ingressus means:

the guest, having entered...

Because ingredior is a deponent verb.

A deponent verb:

• has passive-looking forms
• but an active meaning

So although ingressus looks like a passive participle, with a deponent verb it has an active sense:

• ingressus = having entered, not having been entered

This is one of the most important things to learn about deponent verbs in Latin.

Examples:

• loquor = I speak

• locutus = having spoken

• ingredior = I enter
• ingressus = having entered

Because here ingressus is being used as a participle, not as part of a full perfect tense.

Compare:

1. Hospes ingressus est.
   = The guest entered / has entered.
   Here ingressus est is a finite verb phrase.

2. Hospes in atrium ingressus dominam salutat.
   = The guest, having entered the atrium, greets the lady.
   Here ingressus is a participle modifying hospes.

So Latin can use a participle by itself to add background information, much like English having entered.

Because of agreement.

Ingressus is:

• nominative
• singular
• masculine

So it must describe a noun that is also nominative singular masculine. That matches hospes, not dominam.

• hospes = nominative singular
• dominam = accusative singular feminine

If it described dominam, the form would have to be feminine accusative singular, not ingressus.

So grammar makes the connection clear, even though English relies more heavily on word order.

Yes, hospes can refer to a man or a woman depending on context, since it can mean guest, host, stranger, etc.

But here ingressus is masculine singular, so it tells us that the hospes is being treated as male.

If the guest were female, you would expect:

• Hospes in atrium ingressa dominam salutat.

So the participle helps show gender here.

Because the participle and the finite verb express relative time, not necessarily the same tense in English terms.

• salutat = the main action is present: greets
• ingressus = an action completed before the main action: having entered

So the sequence is:

1. the guest enters the atrium
2. the guest greets the mistress

Latin often uses the perfect participle to show an action completed before the action of the main verb.

That is why English often translates it with:

• having entered
• after entering
• sometimes simply when he had entered

Yes, but it is also very normal Latin.

Latin word order is more flexible than English because the endings show the grammar. This sentence places the participial phrase between the subject and the object/main verb:

• Hospes — subject
• in atrium ingressus — added description
• dominam salutat — main action

This arrangement is natural in Latin and can give a smooth narrative flow:

The guest, having entered the atrium, greets the mistress.

English would usually prefer a different order, but Latin does not need to keep subject, verb, and object tightly together.

Yes. Depending on how natural you want the English to sound, you could translate it several ways:

• having entered the atrium
• after entering the atrium
• when he entered the atrium
• once he had entered the atrium

All of these capture the idea that the entering happens before the greeting.

The most literal participial translation is:

• having entered the atrium

But in smoother English, after entering the atrium is often the most natural.

You should learn it under the deponent verb:

• ingredior, ingredi, ingressus sum

This is the standard dictionary entry.

Its principal parts show you that it is deponent:

• ingredior — I enter
• ingredi — to enter
• ingressus sum — I entered / have entered

From that you can recognize:

• ingressus as the perfect participle
• ingressus est as a perfect tense form
• ingressa, ingressum, etc. as agreeing participial forms

So if you see ingressus, think of ingredior, not of a regular passive verb.