Pater putat frenum a serva nimis celeriter positum esse et ideo mulum calcitrare incipere.

Because it is the subject of an indirect statement after putat.

Latin often uses:

• a main verb of thinking/saying/perceiving
• then an accusative + infinitive construction

So in:

• Pater putat ...
• frenum ... positum esse

the word frenum is not the direct object of putat in the English sense. Instead, it is the subject of the infinitive positum esse, and subjects of infinitives in this construction go into the accusative.

So literally:

• Pater putat frenum positum esse = The father thinks the bridle to have been placed

More natural English:

• The father thinks that the bridle was placed...

Because it agrees with frenum.

Frenum is:

• neuter
• singular
• accusative

The participle positum is part of the perfect passive infinitive positum esse, and the participle must agree with the noun it belongs to:

• masculine: positus
• feminine: posita
• neuter: positum

So:

• frenum positum esse = the bridle to have been placed

If the noun were feminine singular, you would expect positam esse; if masculine singular, positum would become positum only if neuter—so here the neuter form is important evidence that it matches frenum.

Positum esse is the perfect passive infinitive of pono.

Breakdown:

• pono = I place, put
• positum = having been placed/put
• esse = to be

Together:

• positum esse = to have been placed or to have been put

Because it is perfect, it shows an action already completed relative to the main verb:

• Pater putat frenum ... positum esse
  = The father thinks that the bridle has been put on / was put on...

So the idea is that the putting-on happened before the mule’s reaction.

Yes. In a passive construction, the person doing the action is often expressed with:

• a/ab + ablative

So:

• a serva = by the female slave / by the maidservant

This tells you who placed the bridle.

A small detail:

• a is used before most consonants
• ab is often used before vowels and sometimes before consonants too

So a serva is perfectly normal.

Because serva is the agent of a passive verb.

With a passive verb, Latin normally marks the personal doer of the action with:

• a/ab + ablative

Compare:

• serva frenum ponit = the slave woman puts the bridle on
• frenum a serva positum est = the bridle was put on by the slave woman

So once the sentence uses the passive idea positum esse, the doer becomes a serva.

Nimis celeriter means too quickly.

Both are adverbs:

• nimis = too, excessively
• celeriter = quickly

Celeriter is the adverb from celer (quick), and it modifies the action of placing:

• positum esse = to have been placed
• nimis celeriter positum esse = to have been placed too quickly

So this phrase describes how the bridle was put on.

Because the sentence needs an adverb, not an adjective.

An adjective would describe a noun:

• a quick mule
• a quick slave woman

But here the idea is placed quickly, so the word must describe the action of placing.

That is why Latin uses:

• celeriter = quickly

not an adjective.

So:

• nimis celeriter positum esse = to have been placed too quickly

Because this whole part is also inside the scope of putat.

After putat, Latin often continues with infinitives in indirect statement. So:

• mulum is accusative because it is the subject of the infinitives
• incipere is infinitive because it depends on putat
• calcitrare is another infinitive depending on incipere

So literally:

• Pater putat ... mulum calcitrare incipere
• The father thinks the mule to begin to kick

More natural English:

• The father thinks that the mule begins/is beginning to kick
• or The father thinks that the mule starts kicking

Incipere means to begin, and it can take a complementary infinitive.

So:

• incipere calcitrare or calcitrare incipere = to begin to kick

In this sentence:

• mulum = subject of the infinitives
• calcitrare = to kick
• incipere = to begin

Together:

• mulum calcitrare incipere = the mule to begin to kick

Latin word order is flexible, so calcitrare incipere is normal.

Et ideo means and therefore or simply and so.

It connects the two ideas:

1. the bridle was put on too quickly by the slave woman
2. as a result, the mule begins to kick

So the logic is:

• frenum ... nimis celeriter positum esse
• et ideo mulum calcitrare incipere

In smoother English:

• The father thinks that the bridle was put on too quickly by the slave woman, and therefore the mule begins to kick.

Yes, that is the most natural way to read it.

The structure is:

• Pater putat
  [frenum ... positum esse]
  et ideo [mulum calcitrare incipere]

So the father thinks both:

• that the bridle was put on too quickly
• and that, as a result, the mule is beginning to kick

This is a common Latin pattern: one main verb of thinking introduces more than one infinitive clause.

Because Latin relies much more on case endings and much less on fixed word order.

English depends heavily on order:

• The slave woman put the bridle on
• The bridle was put on by the slave woman

Latin can move elements around more freely because the endings show their roles:

• frenum is accusative
• serva is ablative after a
• positum agrees with frenum
• mulum is accusative as subject of the infinitives

So even though the order may feel unusual to an English speaker, the grammar is clear from the forms.

A good way is to find the main verb first, then identify the indirect statement(s).

1. Main verb:

   • Pater putat = The father thinks

2. First indirect statement:

   • frenum a serva nimis celeriter positum esse
   • that the bridle was put on too quickly by the slave woman

3. Second indirect statement/result idea:

   • et ideo mulum calcitrare incipere
   • and therefore that the mule begins/is beginning to kick

So a helpful literal unpacking is:

• The father thinks [the bridle to have been placed too quickly by the slave woman] and therefore [the mule to begin to kick].

Then turn that into natural English.