Mi ne volas kaŝi tiun sekreton de mia patrino.

Because ne usually goes right before the word or phrase it negates. Here it negates volas, so the sentence means I do not want to hide that secret from my mother.

Compare:

• Mi ne volas kaŝi... = I do not want to hide...
• Mi volas ne kaŝi... = I want not to hide...

Both can be similar in meaning, but the first is the normal, most natural way to say it.

Because kaŝi is an infinitive, like to hide in English.

In Esperanto, after verbs like voli (to want), the next verb usually stays in the infinitive:

• Mi volas dormi. = I want to sleep.
• Ŝi volas veni. = She wants to come.

So here:

• volas = the conjugated verb, want
• kaŝi = the infinitive, to hide

Because tiun sekreton is the direct object of kaŝi, and Esperanto marks the direct object with -n.

Also, words that describe or point to a noun agree with that noun. So if the noun takes -n, the demonstrative does too.

• tiu sekreto = that secret
• tiun sekreton = that secret as a direct object

So both words show agreement:

• tiun = accusative form of tiu
• sekreton = accusative form of sekreto

Tiun is the accusative form of tiu, which means that.

Before a noun, tiu works like a demonstrative determiner:

• tiu libro = that book
• tiun libron = that book as an object

So in this sentence:

• tiun sekreton = that secret

Here de mia patrino means from my mother, not of my mother.

With kaŝi, Esperanto often uses de for the person from whom something is hidden:

• kaŝi ion de iu = to hide something from someone

So:

• Mi ne volas kaŝi tiun sekreton de mia patrino. = I do not want to hide that secret from my mother.

Because mia patrino is not the direct object. It is part of the prepositional phrase de mia patrino.

After a preposition like de, you normally do not use the accusative -n just because of object function. So:

• de mia patrino = from my mother
• not de mian patrinon

The direct object is only tiun sekreton.

Because tiu and mia already make the noun definite.

In Esperanto, you normally do not use la together with a demonstrative or a possessive in this kind of phrase:

• tiu sekreto = that secret
• mia patrino = my mother

So:

• not normally la tiu sekreto
• not normally la mia patrino

Both tiu and mia already do the job that the often does in English.

It can look a little ambiguous at first, because de can also mean a relationship like of:

• sekreto de mia patrino could mean a secret of my mother / my mother’s secret

But in this sentence, the verb pattern kaŝi ion de iu strongly suggests hide something from someone. So the intended meaning is from my mother.

If someone wanted to make that extra clear, they could rephrase or change the word order for emphasis.

The sentence uses the normal Esperanto order:

• Mi = subject
• ne volas = verb phrase
• kaŝi tiun sekreton = infinitive phrase with object
• de mia patrino = prepositional phrase

Esperanto word order is fairly flexible because the accusative helps show what the object is. But this version is natural and straightforward.

For example, a speaker could move parts around for emphasis, but the original is the most neutral phrasing.

Ŝ is pronounced like English sh.

So:

• kaŝi sounds roughly like KAH-shee

A few other pronunciations in the sentence:

• volas → VOH-lahs
• tiun → roughly TEE-oon
• sekreton → seh-KREH-ton
• patrino → pah-TREE-no

Esperanto stress normally falls on the second-to-last syllable of each word. So:

• VO-las
• KA-ŝi
• se-KRE-ton
• pa-TRI-no