Aestate saepe cicadae in agris audiuntur.

Aestate is the ablative singular of aestas, meaning summer.

Here it is an example of the ablative of time when, which Latin often uses without a preposition to mean something like in summer or during the summer.

So:

• aestas = summer
• aestate = in summer / during the summer

This is very common in Latin. English usually needs a preposition, but Latin often does not.

Saepe means often. It is an adverb, so it describes the action of the verb: are often heard.

In English, you would usually place it near the verb:

• Cicadas are often heard...
• or In summer, cicadas are often heard...

Latin word order is more flexible than English word order, so saepe can appear in different places without changing the basic meaning.

In this sentence, cicadae is the subject.

That can feel strange to an English speaker at first, because in English we often think of cicadas as the thing being heard, so they seem like an object. But the Latin verb is passive: audiuntur = are heard.

In a passive sentence, the thing receiving the action becomes the subject.

So:

• cicadae = cicadas as the subject of are heard

Grammatically, cicadae is nominative plural.

Because the sentence is passive, not active.

• cicadae = nominative plural
• cicadas = accusative plural

If the sentence were active, you might get something like:

• Aestate saepe cicadas in agris audiunt.
• In summer they often hear cicadas in the fields.

But in your sentence, the meaning is Cicadas are often heard..., so cicadae must be nominative.

In agris uses the ablative plural.

The preposition in takes:

• ablative when it means in / on and shows location
• accusative when it means into / onto and shows motion toward

Here it means in the fields, meaning location, so Latin uses the ablative:

• ager = field
• agris = in the fields (ablative plural after in)

Audiuntur is the 3rd person plural present passive indicative of audio, audire, meaning to hear.

Breakdown:

• audi- = verb stem
• -untur = they are ...-ed for a 4th-conjugation passive verb in the present tense

So audiuntur means:

• they are heard

Since the subject is cicadae (plural), the verb is also plural.

Latin often uses the passive when English might also use either:

• Cicadas are often heard in the fields in summer
• or You often hear cicadas in the fields in summer

The passive is natural here because the sentence focuses on cicadas and the fact that they can be heard, not on who hears them.

So the passive helps put attention on the soundscape rather than on the hearer.

Yes. Latin word order is much more flexible than English word order because the endings show each word’s role.

For example, these would mean basically the same thing:

• Aestate saepe cicadae in agris audiuntur.
• Cicadae aestate saepe in agris audiuntur.
• In agris aestate cicadae saepe audiuntur.

The differences are mostly about emphasis, not basic meaning.

The original order is perfectly natural:

• aestate sets the time first,
• saepe adds frequency,
• cicadae introduces the subject,
• in agris gives the place,
• audiuntur finishes with the verb.

From the endings:

• aestate ends in -e, a common ablative singular ending for many 3rd-declension nouns
• agris ends in -is, a common ablative plural ending for 2nd-declension nouns

So:

• aestate = in summer
• in agris = in the fields

This is one of the most important Latin reading skills: learning to notice what the endings tell you.

Yes. Cicada is a first-declension noun.

Its forms include:

• nominative singular: cicada
• nominative plural: cicadae
• accusative plural: cicadas

So in this sentence, cicadae is the nominative plural form.

A helpful way to parse it is:

• Aestate = time: in summer
• saepe = frequency: often
• cicadae = subject: cicadas
• in agris = place: in the fields
• audiuntur = verb: are heard

So the sentence works like this:

In summer, cicadas are often heard in the fields.

That is a good example of how Latin often builds a sentence out of clear parts marked by endings rather than by fixed word order.