Il dizionario non solo spiega il significato di una parola, ma anche la sua pronuncia.

It means not only ... but also.

So in this sentence:

Il dizionario non solo spiega il significato di una parola, ma anche la sua pronuncia.

the pattern is:

• non solo = not only
• ma anche = but also

This is a very common structure in Italian, just like in English.

A literal breakdown would be:

• Il dizionario = the dictionary
• non solo spiega = not only explains
• il significato di una parola = the meaning of a word
• ma anche la sua pronuncia = but also its pronunciation

Italian often uses this structure exactly the way English does.

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

Il dizionario means the dictionary, and here it refers to the dictionary as a general type of thing, or to a dictionary in a general statement.

Italian often prefers the article in places where English might sometimes leave it out. For example:

• Il cane è un animale fedele. = The dog is a faithful animal / Dogs are faithful animals.
• Il dizionario è utile. = The dictionary is useful / Dictionaries are useful.

So Il dizionario sounds natural in a general statement.

Spiega is the third-person singular present tense of spiegare = to explain.

The subject is Il dizionario, which is singular, so the verb must also be singular:

• io spiego = I explain
• tu spieghi = you explain
• lui/lei spiega = he/she explains

So:

• Il dizionario spiega = the dictionary explains

That is why you get spiega, not spiegare or spieghi.

Because Italian normally uses articles before nouns much more consistently than English does.

So:

• il significato = the meaning
• la sua pronuncia = its pronunciation / its own pronunciation

Even when English might say just meaning or pronunciation, Italian often wants an article.

Also, with possessives, Italian usually keeps the definite article:

• il mio libro = my book
• la sua pronuncia = its pronunciation / his pronunciation / her pronunciation

So la sua pronuncia is completely normal Italian.

Because una parola means a word, in a general sense.

The sentence is talking about what a dictionary does in general: it explains the meaning of a word, not the meaning of one specific word already known in the conversation.

Compare:

• di una parola = of a word / of any word
• della parola = of the word / of that specific word

So il significato di una parola means the meaning of a word in a general, indefinite sense.

Sua refers to una parola.

So la sua pronuncia means its pronunciation, that is, the pronunciation of the word.

This is a very important point: in Italian, the possessive agrees with the thing possessed, not with the owner.

Here:

• pronuncia is feminine singular
• so the possessive is sua

Even though parola is also feminine, the form sua is chosen because of pronuncia, the noun being possessed.

Compare:

• la sua pronuncia = its pronunciation
• il suo significato = its meaning

The possessive changes with pronuncia / significato, not with the owner.

Because in Italian, possessives usually come with the definite article.

So Italian says:

• il mio libro = my book
• la tua macchina = your car
• la sua pronuncia = its pronunciation

English does not use an article here, but Italian usually does.

One major exception is with some singular family nouns:

• mia madre = my mother
• tuo fratello = your brother

But pronuncia is not a family noun, so the article stays:

• la sua pronuncia

The comma helps separate the two parts of the non solo ... ma anche structure.

It is similar to English punctuation in a sentence like:

• The dictionary explains not only the meaning of a word, but also its pronunciation.

In Italian, the comma is common and helps readability, especially when the first part is a bit long.

You may sometimes see slight punctuation variation depending on style, but the comma here is perfectly natural.

Yes, absolutely.

That version is also very natural:

Il dizionario spiega non solo il significato di una parola, ma anche la sua pronuncia.

The difference is just where the emphasis falls:

• non solo spiega ... emphasizes the action explains
• spiega non solo il significato ... emphasizes the first object, the meaning

In this sentence, both are correct and natural.

A simple pronunciation guide:

• Il ≈ eel
• dizionario ≈ dee-tsyo-NAH-ryo
• non solo ≈ non SO-lo
• spiega ≈ spyeh-ga
• il significato ≈ eel seen-yee-fee-KAH-to
• di una parola ≈ dee OO-na pa-RO-la
• ma anche ≈ ma AN-keh
• la sua pronuncia ≈ la SOO-a pro-NOON-cha

A fuller approximation of the whole sentence:

eel dee-tsyo-NAH-ryo non SO-lo spyeh-ga eel seen-yee-fee-KAH-to dee OO-na pa-RO-la, ma AN-keh la SOO-a pro-NOON-cha

A couple of useful pronunciation notes:

• gli, gn, and some Italian consonants are tricky, but none of those appear here.
• ci/cia/ciare-type sounds matter here: pronuncia ends with a -cha sound.
• In spiega, ie does not make two fully separate syllables in the English sense; it flows together as spyeh.

In careful, standard Italian, non solo ... ma anche is the full balanced structure, and that is what learners should use.

So this is the best model:

• non solo ..., ma anche ...

Sometimes in speech or less formal writing, Italians may shorten or vary the structure, but for learning purposes, it is best to keep both parts together.

So in this sentence, ma anche is the expected and natural continuation of non solo.