Il pallonetto rimbalza contro la parete di vetro.

Pallonetto is a sports word. It usually refers to a lob: a shot that sends the ball up and over the opponent. In racket sports, especially contexts like tennis, padel, or similar games, that is the most likely meaning.

It is a masculine singular noun, which is why it takes il.

Italian uses different forms of the depending on the sound that follows.

You use il before most masculine singular nouns:

• il libro
• il tavolo
• il pallonetto

You use lo before masculine singular nouns beginning with:

• s + consonant: lo sport
• z: lo zaino
• ps, gn, x, y, etc.

Since pallonetto starts with a normal p followed by a vowel, the correct article is il.

Rimbalza is the third person singular present tense of rimbalzare (to bounce).

So the pattern is:

• io rimbalzo = I bounce
• tu rimbalzi = you bounce
• lui/lei rimbalza = he/she/it bounces

Here the subject is il pallonetto, which is singular, so rimbalza is the correct form.

Italian usually does not use a subject pronoun when the subject is already clear from the verb or is explicitly stated.

In this sentence, the subject is already present:

• Il pallonetto rimbalza...

So Italian does not need an extra word for it. A literal English-style version like Esso rimbalza would sound unnatural in normal speech.

Contro means against.

It is used when something moves and makes contact with a surface or object:

• sbattere contro il muro = to crash into the wall
• lanciare la palla contro la porta = to throw the ball against the goal
• rimbalzare contro la parete = to bounce against the wall

So contro is the natural preposition here because the ball is bouncing against the glass wall.

La parete means the wall, while di vetro describes what it is made of: of glass / glass.

So:

• la parete = the wall
• di vetro = made of glass

Italian often uses di + material where English may simply use the material as an adjective:

• un tavolo di legno = a wooden table
• una statua di marmo = a marble statue
• una parete di vetro = a glass wall

Yes, parete in vetro is possible, and it also means glass wall. But there is a slight nuance.

• di vetro is the most straightforward way to say it is made of glass.
• in vetro can also mean made of glass, and sometimes sounds a bit more descriptive or technical depending on context.

In a simple sentence like this, parete di vetro sounds very natural.

This is the most neutral Italian word order:

subject + verb + prepositional phrase

So:

• Il pallonetto = subject
• rimbalza = verb
• contro la parete di vetro = where/how it bounces

Italian can sometimes change word order for emphasis, but this version is the standard, unmarked one.

Often yes, but the exact use can depend on context.

Rimbalzare can mean:

• a ball physically bouncing
• something rebounding off a surface
• sometimes even ideas/news “bouncing around” in a figurative sense

In this sentence, it is the literal physical meaning: the ball rebounds after hitting the glass wall.

You would change the noun and any related article or verb as needed.

For more than one lob shot:

• I pallonetti rimbalzano contro la parete di vetro.
  • i pallonetti = the lob shots
  • rimbalzano = bounce

For more than one wall:

• Il pallonetto rimbalza contro le pareti di vetro.
  • le pareti = the walls

So the verb must agree with the subject:

• singular subject → rimbalza
• plural subject → rimbalzano

Roughly: pal-lo-NET-to

A few useful points:

• the double ll is clearly pronounced
• the stress is on -net-
• the double tt is also pronounced more strongly than a single t

So it is not said like one smooth English word; the doubled consonants matter in Italian pronunciation.