Il cavo del cambio muove il deragliatore.

Because Italian usually uses the definite article with nouns more often than English does.

• il cavo = the cable
• il deragliatore = the derailleur

In a technical sentence like this, Italian normally keeps the articles. English might sometimes say something more compact like gear cable moves derailleur, but standard Italian prefers il cavo del cambio muove il deragliatore.

Del is a contraction of di + il.

• di = of
• il = the
• di + il = del

So:

• il cavo del cambio = the cable of the gear mechanism / the gear cable

This is a very common Italian pattern:

• la porta del garage = the garage door
• il colore del muro = the color of the wall

Because Italian normally expresses this kind of relationship with di.

English often puts one noun in front of another:

• gear cable
• car door
• bike seat

Italian usually does not do that in the same way. It prefers:

• il cavo del cambio
• la portiera della macchina
• il sellino della bici

So del cambio is the normal Italian way to say of the gear system / gear-related.

Muove is the third-person singular present tense of muovere.

So the pattern is:

• io muovo = I move
• tu muovi = you move
• lui/lei muove = he/she/it moves

In this sentence, the subject is il cavo del cambio, which is singular, so the verb must also be singular:

• Il cavo del cambio muove...

Because the basic Italian word order is usually the same as in English:

subject + verb + object

Here that gives:

• Il cavo del cambio = subject
• muove = verb
• il deragliatore = object

So the sentence structure is very straightforward.

In this sentence, word order tells you.

• Il cavo del cambio comes before the verb, so it is the subject.
• il deragliatore comes after the verb, so it is the direct object.

Italian does not mark the direct object with a special ending here, so position is important in a simple sentence like this.

Because cambio is a masculine singular noun, so it takes il:

• il cambio

The same is true for:

• il cavo
• il deragliatore

All three nouns in this sentence are masculine singular, which is why you see il and del rather than feminine forms like la or della.

No. Here cambio is a noun, not a verb.

As a noun, il cambio can mean things like:

• gear mechanism
• gear system
• shift mechanism
• in other contexts, exchange or change

But the verb cambiare means to change.

So:

• il cambio = the gear system / the change / the exchange
• cambiare = to change

Possibly, depending on context, but muove is a very natural choice.

• muovere = to move
• spostare = to move something from one position to another, to shift/reposition

In a mechanical explanation, muove is simple and idiomatic: the cable moves the derailleur.
Sposta could work in some contexts, but it sounds slightly more focused on changing position rather than causing motion in general.

Because article omission works differently in Italian.

English often shortens technical labels:

• brake cable
• gear cable
• rear derailleur

Italian usually still wants an article in a full sentence:

• il cavo del freno
• il cavo del cambio
• il deragliatore posteriore

So in normal grammar, il is expected here.

Yes, but the neutral, standard order is the one you see here.

Normal order:

• Il cavo del cambio muove il deragliatore.

You could change the order for emphasis, but it would sound less neutral. For example, putting the object first might emphasize the derailleur. In most learner contexts, it is best to stick with the standard subject + verb + object order.

The tricky part is gli before a vowel.

In deragliatore, the gli is not pronounced like regular English gl. It has the Italian gli sound, similar to the lli in some pronunciations of million, but more clearly palatal.

A rough guide is:

• de-ra-glia-TO-re

The stress is on to: deragliaTOre.

This is a sound English speakers often need practice with.

Because il deragliatore is the direct object of the verb muovere.

The pattern is:

• muovere qualcosa = to move something

So:

• muove il deragliatore = moves the derailleur

No preposition is needed, just as in English:

• moves the derailleur not
• moves to the derailleur

Yes. If you made the nouns plural, the articles and the verb would also have to agree.

For example:

• I cavi del cambio muovono i deragliatori.

Changes:

• il cavo → i cavi
• muove → muovono
• il deragliatore → i deragliatori

This is a good example of agreement in Italian: articles, nouns, and verbs all change to match number.