Pecus aquam bibit.

The clearest clue is aquam. The ending -am shows the accusative singular, which is the usual case for a direct object. So aquam is the thing being drunk.

That leaves pecus as the subject, the one doing the drinking. The verb bibit is also 3rd person singular, so it matches a singular subject.

One small complication: pecus is a neuter noun, and in neuter nouns the nominative and accusative are often identical. So the form pecus could in theory be either nominative or accusative. In this sentence, though, aquam is already clearly the object, so pecus must be the subject.

Because aquam is the accusative form of aqua.

The dictionary form is aqua, meaning water. But when Latin uses it as a direct object after a verb like bibit, it changes to aquam.

So:

• aqua = nominative, used for the subject
• aquam = accusative, used for the direct object

Latin often shows a word’s role in the sentence by changing its ending.

Here, pecus is nominative singular.

It is the subject of bibit, so nominative is the case we expect. The tricky part is that pecus is a neuter noun, and neuter nouns often have the same form for nominative and accusative. So the form by itself does not tell you everything; you have to look at the whole sentence.

Because aquam is clearly accusative, pecus must be nominative here.

No. Pecus is actually neuter, not masculine.

This is a very common beginner question, because English-speaking learners often associate -us with masculine second-declension nouns like servus. But pecus is different: it is a third-declension neuter noun, with dictionary form pecus, pecoris.

So the ending -us does not always mean:

• masculine
• second declension

You always have to learn the noun’s gender and declension from its dictionary entry.

Pecus can mean something like cattle, livestock, a herd, a flock, or sometimes a beast/animal, depending on context.

It is often a collective word, so even though it is grammatically singular here, its meaning can be broader than just one individual creature.

In this sentence, the exact English wording depends on the meaning your textbook has already given you, but the important grammar point is that pecus is singular in form and takes the singular verb bibit.

Bibit is 3rd person singular from the verb bibo, bibere, meaning to drink.

In a beginner sentence like this, it is usually understood as drinks.

A more advanced point: when macrons are not written, bibit can be ambiguous in spelling:

• bĭbit = drinks (present)
• bībit = drank / has drunk (perfect)

So in ordinary printed Latin without vowel marks, context has to tell you which meaning is intended. Since the meaning has already been given to the learner, you would follow that meaning here.

Because Latin does not have articles like English the and a/an.

Latin often leaves that idea to context. So pecus could be translated as the herd, a herd, the animal, or an animal, depending on what makes sense in context. The same is true for aquam: English might say water, the water, or even some water.

When translating into English, you add the article that sounds natural.

The order pecus aquam bibit is perfectly normal, and it follows a common textbook pattern: subject + object + verb.

But Latin word order is much more flexible than English word order, because the endings already show each word’s role. So these could mean basically the same thing:

• Pecus aquam bibit
• Aquam pecus bibit
• Bibit pecus aquam

The difference is usually one of emphasis or style, not basic meaning.

In a restored Classical pronunciation, a good approximation is:

PEH-koos AH-kwam BIH-bit

A few helpful points:

• c is always hard, like k
• qu sounds like kw
• u is pronounced like oo
• the stress is usually PÉ-cus, Á-quam, BÍ-bit

If your course uses ecclesiastical pronunciation, some details may differ, but qu is still basically kw here.