Odi murmur in bibliotheca, quia, cum id audio, frustra legere conor.

Because odi belongs to a small group of Latin verbs whose perfect forms are used with a present meaning. So:

• odi = I hate
• not I hated

This verb is often called defective, because it does not use the full normal set of forms. Historically, the idea is something like I have come to hate, which developed into the simple present sense I hate.

So in this sentence, odi murmur means I hate the murmur/murmuring, not I hated it.

Murmur is the direct object of odi, so it is in the accusative case.

The reason it still looks like murmur is that it is a neuter third-declension noun. In Latin, neuter nouns have an important pattern:

• nominative singular = accusative singular
• nominative plural = accusative plural

So murmur can be either nominative singular or accusative singular depending on its job in the sentence. Here it is accusative because it is the thing being hated.

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

So a noun like murmur can mean:

• a murmur
• the murmur
• sometimes just murmuring in a more general sense

The exact force depends on context. The same is true for bibliotheca: Latin does not need a separate word for the library.

Because in can take either the ablative or the accusative, depending on meaning:

• in + ablative = in/on a place, with no movement
• in + accusative = into/onto a place, with movement toward it

Here the meaning is location: the murmur is happening in the library, not moving into the library. So Latin uses the ablative:

• in bibliotheca = in the library

It is the same spelling, but not the same use.

Latin cum can be:

• a preposition meaning with when followed by a noun in the ablative
• a conjunction meaning when, since, or although when it introduces a clause

Here it is a conjunction, because it introduces the clause cum id audio.

So here cum means when:

• cum id audio = when I hear it

Id is a pronoun meaning it. It refers back to murmur.

Because murmur is neuter singular, the pronoun referring to it is also neuter singular:

• murmur → id

Its case is accusative here because it is the direct object of audio:

• audio id = I hear it

So id agrees with what it refers to in gender and number, but its case depends on its role in its own clause.

Because the sentence describes a general, repeated situation rather than one single event in the past.

The idea is something like:

• I hate murmuring in the library because, whenever I hear it, I try in vain to read.

Latin often uses the present tense for this kind of general truth or habitual action. So audio means I hear in the sense of whenever I hear it.

Frustra is an adverb meaning in vain, fruitlessly, or to no purpose.

It describes the attempt expressed by legere conor. In other words, it tells you that the trying is unsuccessful:

• frustra legere conor = I try to read, but without success
• more naturally: I try in vain to read

So frustra modifies the verbal idea of trying to read, not the noun murmur.

Because conor means I try or I attempt, and verbs like try are commonly followed by an infinitive expressing what the subject tries to do.

So:

• conor = I try
• legere = to read
• legere conor = I try to read

This is called a complementary infinitive: the infinitive completes the meaning of the main verb.

Because conor is a deponent verb.

Deponent verbs have:

• passive-looking forms
• but active meanings

So although conor looks like a passive form, it means I try, not I am tried.

Its dictionary form is:

• conor, conari, conatus sum

A learner often has to get used to this pattern, because deponent verbs are very common in Latin.

Yes, the word order is somewhat flexible, and Latin often arranges words for emphasis or style rather than following a fixed English-like order.

This sentence begins with the main emotional point:

• Odi murmur = I hate the murmur/murmuring

Then it gives the reason:

• quia = because

And inside that reason, it inserts a time clause:

• cum id audio = when I hear it

Finally, the sentence ends with the main action of that reason clause:

• frustra legere conor = I try in vain to read

Latin can do this because endings show grammatical relationships. English depends much more heavily on word order, so the Latin arrangement may feel less direct to an English speaker.

The commas help show the structure of the clauses:

• main clause: Odi murmur in bibliotheca
• reason clause: quia ... conor
• time clause inside it: cum id audio

So the punctuation is there to help the reader see that cum id audio is inserted inside the quia clause.

It is also worth remembering that ancient Latin texts were not punctuated in the same modern way. The commas you see are part of modern editorial practice, meant to make the sentence easier to read.