Ĉi tiu aparato bezonas kablon.

Yes. ĉi tiu means this.

A helpful way to think about it is:

• tiu = that
• ĉi adds the idea of nearness
• so ĉi tiu = this

Esperanto also allows tiu ĉi, so both of these are correct:

• ĉi tiu aparato
• tiu ĉi aparato

Both mean this device.

In Esperanto, nouns normally end in -o. So:

• aparato = device, apparatus

That -o ending tells you the word is a noun. This is one of the most regular features of Esperanto.

For example:

• kablo = cable
• aparato = device
• domo = house

Because -as is the present-tense verb ending in Esperanto.

So:

• bezoni = to need
• bezonas = needs / need

In this sentence, the subject is Ĉi tiu aparato (this device), so bezonas means needs.

Other common verb endings are:

• -is = past
• -os = future
• -us = conditional
• -u = command / wish
• -i = infinitive

So:

• La aparato bezonis kablon. = The device needed a cable.
• La aparato bezonos kablon. = The device will need a cable.

Because kablon is the direct object of the verb bezonas.

In Esperanto, the direct object usually takes the accusative ending -n.

So:

• kablo = a cable
• kablon = a cable (as the direct object)

Here, the device is doing the needing, and the cable is the thing being needed. That makes kablon the direct object.

Compare:

• La aparato bezonas kablon.
• Mi vidas hundon.
• Ŝi havas libron.

In each case, the thing directly affected by the verb gets -n.

Yes, in standard Esperanto that would be wrong.

Because bezoni is a transitive verb, it takes a direct object, and the direct object needs -n. So you need:

• Ĉi tiu aparato bezonas kablon.

not

• Ĉi tiu aparato bezonas kablo

The -n is an important grammar marker, not an optional extra.

Esperanto has a definite article, la, for the, but it does not have an indefinite article like English a/an.

So:

• kablo can mean a cable or just cable, depending on context
• la kablo means the cable

In this sentence, kablon naturally comes across as a cable in English, even though Esperanto does not use a separate word for a.

So:

• bezonas kablon = needs a cable
• bezonas la kablon = needs the cable

Yes, Esperanto word order is fairly flexible, mainly because endings like -n show the grammatical role.

The most neutral order is:

• Ĉi tiu aparato bezonas kablon.

But other orders are possible, for example:

• Kablon bezonas ĉi tiu aparato.

That puts more emphasis on kablon.

Even with changed word order, the -n on kablon still shows that it is the object, not the subject.

That said, beginners should usually stick with the normal order:

subject + verb + object

Actually, it already matches in the way it needs to.

In Esperanto, adjectives can take -j for plural and -n for accusative when appropriate. Demonstratives like tiu can also take those endings when needed.

Here everything is singular, and the noun aparato is the subject, so no extra ending is needed:

• ĉi tiu aparato = this device

If it were plural, you would get:

• ĉi tiuj aparatoj = these devices

If it were a direct object, you could get:

• Mi vidas ĉi tiun aparaton. = I see this device.

So tiu can change; it just doesn’t need to in your original sentence.

Usually, no.

ĉi is normally used together with a word like tiu or tio to indicate nearness:

• ĉi tiu / tiu ĉi = this
• ĉi tio / tio ĉi = this thing, this

So you would not normally use ĉi alone to mean this.

A rough pronunciation guide is:

chee TEE-oo ah-pah-RAH-to beh-ZOH-nahs KAH-blon

A few helpful points:

• ĉ sounds like ch in church
• tiu is roughly TEE-oo
• stress in Esperanto is usually on the second-to-last syllable

So:

• a-pa-RA-to
• be-ZO-nas
• KA-blon

Esperanto spelling and pronunciation are very regular, much more so than in English.

It works very much like English need in this sentence.

Structure:

• [subject] + bezonas + [direct object]

So:

• Mi bezonas helpon. = I need help.
• Ŝi bezonas tempon. = She needs time.
• La aŭto bezonas riparon. = The car needs a repair.

So Ĉi tiu aparato bezonas kablon is a very normal and straightforward Esperanto sentence pattern.