Agnus, quem soror in manibus tenet, iam non balat.

Because quem is the accusative singular masculine form of the relative pronoun.

It refers back to agnus (the lamb), so it matches agnus in:

• gender: masculine
• number: singular

But its case depends on its job inside the relative clause. In quem soror in manibus tenet, quem is the direct object of tenet (holds), so it must be accusative.

So:

• agnus = nominative, because it is the subject of balat
• quem = accusative, because it is the object of tenet

Agnus is the subject of the main verb balat.

So the basic main clause is:

• Agnus ... iam non balat
  = The lamb ... is no longer bleating

The relative clause quem soror in manibus tenet just gives extra information about that lamb.

Because soror is the subject of tenet in the relative clause.

In:

• quem soror in manibus tenet

the sister is doing the holding, so soror must be nominative.

A quick breakdown:

• quem = the lamb, being held
• soror = the sister, doing the holding
• tenet = holds

So the clause means:

• whom the sister is holding in her hands

The relative clause is:

• quem soror in manibus tenet

It describes agnus.

A literal structure would be:

• The lamb, whom the sister holds in her hands, no longer bleats.

In smoother English, we usually say:

• The lamb that the sister is holding in her hands no longer bleats.

Latin often uses a relative pronoun where English might use that.

Manibus is ablative plural.

It follows the preposition in, which here means in/on/within and takes the ablative when it expresses location.

So:

• in manibus = in the hands

This tells you where the lamb is being held.

Also, manus is a fourth-declension noun, so its ablative plural is manibus.

Latin often uses the plural for body parts that naturally come in pairs, especially with things like hands, eyes, ears, and feet.

So:

• in manibus = in her hands

This is very natural Latin. Even if English might sometimes say in her arms or in her hands, Latin commonly uses the plural here.

Also, Latin does not need to say her explicitly, because the context already makes it clear that the hands belong to soror.

Iam often means now, already, or by now, depending on context.

With non, it commonly gives the sense:

• no longer
• not anymore

So:

• iam non balat = is no longer bleating

This is more natural than translating it word-for-word as now not bleats.

Balat is:

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

from the verb balare, meaning to bleat.

So balat means:

• he/she/it bleats
• here: it is bleating or it bleats

Since the subject is agnus, the meaning is:

• the lamb bleats
• in this sentence, with iam non: the lamb no longer bleats

Tenet is:

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

from tenere, meaning to hold.

Its subject is soror, and its object is quem.

So:

• soror ... tenet = the sister holds
• quem soror in manibus tenet = whom the sister is holding in her hands

Because Latin has no articles.

So agnus can mean:

• a lamb
• the lamb

and soror can mean:

• a sister
• the sister

You decide from the context which English article fits best.

That is why the same Latin sentence could be translated in slightly different ways depending on the situation.

Yes, but it is very normal for Latin.

The sentence is:

• Agnus, quem soror in manibus tenet, iam non balat.

Latin often places:

• the main subject first
• an inserted relative clause next
• the main verb near the end

So the structure is:

1. Agnus = main subject
2. quem soror in manibus tenet = relative clause describing the lamb
3. iam non balat = main statement about the lamb

English usually prefers a more fixed word order, but Latin can move words around more freely because the endings show their grammatical roles.

They mark off the relative clause as an inserted descriptive unit.

In printed Latin, punctuation helps the reader see the structure:

• main clause beginning
• relative clause in the middle
• main clause continuing afterward

Older Latin texts did not always use punctuation the way modern editions do, so the commas are mainly a reading aid.

Quem is masculine because it agrees with agnus, and agnus is a masculine noun.

In Latin, grammatical gender belongs to the noun itself. So even if you are thinking about an actual animal, the pronoun must match the noun’s grammatical gender.

Since:

• agnus = masculine

the relative pronoun must be masculine too:

• quem = masculine accusative singular

If the antecedent were feminine, you would expect quam instead.