Mi preferas tiun ĝenron.

In Esperanto, -as marks the present tense.

So:

• preferi = to prefer
• preferas = prefer / am preferring
• preferis = preferred
• preferos = will prefer

A very useful rule is that Esperanto verbs do not change according to the subject:

• mi preferas = I prefer
• vi preferas = you prefer
• li preferas = he prefers

That makes verb conjugation much simpler than in English.

Because tiun is the direct object of the verb, so it takes the accusative ending -n.

Here, the thing being preferred is that genre, so Esperanto marks it with -n:

• tiu ĝenro = that genre
• tiun ĝenron = that genre (as a direct object)

In this sentence, tiun goes with ĝenron, and both show the object function.

For the same reason: it is part of the direct object.

Esperanto often marks the direct object with -n. Since tiun and ĝenron belong together, they both show that relationship:

• ĝenro = genre
• ĝenron = genre (object form)

This matching is an example of agreement. Words that go together often match in number and case.

The basic form is ĝenro.

You can break it down like this:

• ĝenro = genre
• -n = direct object marker

So ĝenron is just ĝenro with the accusative ending added.

ĝ is pronounced roughly like the j in judge.

So ĝenro sounds approximately like:

• JEN-ro

A few pronunciation notes:

• ĝ = English j sound
• e = like e in met
• r is usually trilled or tapped, depending on the speaker
• every letter is pronounced clearly

So ĝenron is roughly JEN-ron.

Usually tiu means that.

So:

• tiu = that
• ĉi tiu or tiu ĉi = this

Examples:

• tiu ĝenro = that genre
• ĉi tiu ĝenro = this genre

So if the sentence is Mi preferas tiun ĝenron, the most natural reading is I prefer that genre.

Because tiun already makes the noun definite enough.

Esperanto uses la for the, but you normally do not use la together with a demonstrative like tiu.

So:

• la ĝenro = the genre
• tiu ĝenro = that genre

You would not normally say la tiu ĝenro.

No, Esperanto word order is fairly flexible, because the -n ending helps show what the object is.

The normal order here is:

• Mi preferas tiun ĝenron.
• subject + verb + object

But you could also say:

• Tiun ĝenron mi preferas.

That version gives more emphasis to that genre. Both are grammatical.

Yes. Preferi works very much like English to prefer in this kind of sentence.

So:

• Mi preferas tiun ĝenron. = I prefer that genre.
• Ŝi preferas teon. = She prefers tea.

You can also compare two things:

• Mi preferas teon al kafo. = I prefer tea to coffee.

So using preferi with a direct object is completely normal.

Mi means I.

Unlike English, Esperanto pronouns can take -n if they are direct objects:

• mi = I
• min = me (as a direct object)

Examples:

• Mi vidas vin. = I see you.
• Li vidas min. = He sees me.

In your sentence, mi is the subject, so it stays mi.

It is a borrowed word, similar to genre in English and other European languages.

That is very common in Esperanto. Even borrowed words follow regular Esperanto grammar:

• ĝenro = genre
• ĝenroj = genres
• ĝenron = genre (object form)
• ĝenrojn = genres (object plural)

So even when a word comes from another language, Esperanto treats it in a very regular way.