La memoria del telefono è piena.

Del means of the. It is a contraction of di + il:

• di = of
• il = the
• del = of the

So:

• la memoria del telefono = the memory of the phone / the phone’s memory

Italian often uses this of the structure where English might prefer a possessive.

Yes, memoria can mean human memory, but it is also the normal word for memory/storage in devices such as phones, computers, and tablets.

So in this sentence, la memoria del telefono means the phone’s storage or memory capacity.

Because piena agrees with memoria, which is a feminine singular noun.

• memoria = feminine singular
• adjective must match it
• so: piena = feminine singular form of pieno

Compare:

• Il telefono è pieno. = The phone is full.
• La memoria è piena. = The memory is full.

È means is, from the verb essere (to be).

It has an accent to distinguish it from e, which means and.

• è = is
• e = and

So the accent is very important in writing.

Italian usually expresses possession differently from English. Instead of using ’s, it often uses:

• noun + di + article + noun

So:

• the phone’s memory
  becomes
• la memoria del telefono

This is one of the most common ways to show possession in Italian.

Yes. That is very natural too.

• telefono = phone
• cellulare = mobile phone / cell phone

In everyday Italian, many people would say cellulare if they specifically mean a mobile phone.
So both are possible, depending on context.

Because memoria is a singular feminine noun, so it takes the definite article la.

• la memoria = the memory

Italian uses articles very often, sometimes more often than English does, so including la here is normal and necessary.

Yes. Telefono is a masculine singular noun.

That is why:

• il telefono = the phone
• del telefono = of the phone

Since del comes from di + il, the masculine article matters.

Yes, that is a correct literal translation.

A more natural English translation is often:

• The phone’s memory is full.
• The phone storage is full.

But grammatically, the Italian structure is very close to the memory of the phone.

For this meaning, piena is the normal choice.

• piena = full

If a phone’s memory has no space left, la memoria del telefono è piena sounds natural.
Other adjectives would usually change the meaning.

You may also hear:

• La memoria del telefono è quasi piena. = The phone’s memory is almost full.
• La memoria del telefono è occupata. = The phone’s memory is occupied.

But piena is the basic and most direct way to say it.

The structure is:

• La memoria del telefono = subject
• è = verb
• piena = adjective/complement

So the pattern is essentially:

• subject + is + adjective

This is very similar to English:

• The phone’s memory is full.

Yes, if the context is already clear, Italians may shorten it.

For example:

• La memoria è piena. = The memory is full.
• È piena. = It’s full.

But the full sentence La memoria del telefono è piena is perfectly natural when you want to be specific.

Piena is pronounced roughly PYEH-na.

A helpful breakdown:

• pie in Italian often sounds like pyeh
• na = nah

So: PYEH-na

Also note that ie here is not pronounced like English pee-na. The stress is on the first syllable:

• PIE-na