Postea anates e horto ad aquam ambulant, et gallus eas spectat.

Postea is an adverb meaning afterward, later, or then. It sets the time for the whole sentence.

Latin often puts a time word near the beginning of a sentence, but it does not have to be there. So Postea anates... means Afterward, the ducks...

Anates is the nominative plural of anas, meaning duck. This noun belongs to the third declension, so its plural forms are not like first-declension nouns such as puella → puellae.

The basic forms are:

• anas = duck
• anates = ducks

Here anates is the subject of ambulant, so it must be in the nominative plural.

The verb ambulant ends in -nt, which tells you the subject is they. Since anates is a nominative plural noun and fits that verb, it is the subject.

So:

• anates = the ducks
• ambulant = they walk

Together: the ducks walk

The preposition e (or ex) means out of or from. It takes the ablative case, so hortus becomes horto.

So:

• hortus = garden
• e horto = out of the garden / from the garden

This is why you do not see hortus here.

Both e and ex mean the same thing here: out of / from. Latin uses both forms, and the choice is often based on sound.

A common tendency is:

• e before many consonants
• ex often before vowels or for ease of pronunciation

So e horto is perfectly normal. Ex horto would also be understandable.

Ad means to or toward, and it shows movement in the direction of something. Since the ducks are walking toward the water, Latin uses ad.

So:

• ad aquam = to the water / toward the water

Aquam by itself would just be the accusative form of aqua, but without a preposition it would not clearly mean to the water here.

In aquam would mean into the water, which is a different idea. Ad aquam suggests movement up to the water, not necessarily into it.

Because ad takes the accusative case.

The noun is:

• aqua = water
• aquam = water, in the accusative singular

So ad aquam is a standard prepositional phrase: to the water.

Because its subject, anates, is plural.

The verb ambulat means he/she/it walks.
The verb ambulant means they walk.

Since there are multiple ducks, Latin uses ambulant.

Because the sentence has two different clauses with two different subjects:

1. Postea anates e horto ad aquam ambulant

   • subject: anates = the ducks
   • verb: ambulant = walk / are walking

2. et gallus eas spectat

   • subject: gallus = the rooster
   • verb: spectat = watches / is watching

So the ducks are plural, but the rooster is just one animal, so gallus is singular.

Eas means them, referring back to anates.

It is a pronoun used as the direct object of spectat:

• gallus = the rooster
• spectat = watches
• eas = them

So gallus eas spectat means the rooster watches them.

Latin often uses a pronoun like this when English would also use them.

Because eas is feminine accusative plural, and it agrees with anates, which is feminine.

So:

• eas = them, feminine plural
• eos = them, masculine plural

Since the pronoun refers to anates, Latin uses eas.

Eas is accusative plural feminine.

It is accusative because it is the direct object of spectat. The rooster is doing the watching, and the ducks are the ones being watched.

So the structure is:

• gallus = subject
• spectat = verb
• eas = direct object

Yes, it could come after. Latin word order is more flexible than English because the endings show the grammatical roles.

So these would all be understandable:

• gallus eas spectat
• gallus spectat eas
• eas gallus spectat

The version in your sentence places eas before spectat, but the meaning stays the same: the rooster watches them.

Classical Latin has no definite article like English the and no indefinite article like a/an.

So:

• anates can mean ducks or the ducks
• gallus can mean a rooster or the rooster

You decide from context which English translation sounds best.

Spectat can mean looks at, watches, or observes, depending on context.

Here, since the rooster is looking at the ducks as they walk, English might translate it as either:

• looks at them
• watches them

Both fit the Latin well.

Very literal word-by-word, it is something like:

Afterward ducks out of the garden to the water walk, and rooster them watches.

That sounds unnatural in English, but it shows how Latin is built.

A more natural English order is:

Afterward the ducks walk from the garden to the water, and the rooster watches them.

So one important thing for learners is that Latin word order is often guided more by emphasis and style than by strict subject-verb-object order.