In occasione del compleanno di Anna, preparo una torta.

Yes. In occasione di is a common Italian expression meaning on the occasion of, for, or to mark something.

So:

• in occasione del compleanno di Anna = on the occasion of Anna’s birthday

It is a slightly more formal or polished way to introduce the reason for an action. In everyday speech, Italians often also say:

• Per il compleanno di Anna, preparo una torta.

Both are correct.

Because del is the contracted form of di + il.

• di + il = del

So:

• in occasione di + il compleanno becomes
• in occasione del compleanno

This kind of contraction is very common in Italian:

• di + il = del
• di + lo = dello
• di + la = della
• di + i = dei
• di + gli = degli
• di + le = delle

In standard Italian, names of people usually do not take an article after di.

So you say:

• il compleanno di Anna
• la macchina di Marco
• il libro di Giulia

not normally:

• il compleanno dell’Anna

In some regional varieties, especially in parts of northern Italy, people may use an article before first names in speech, but for learners, di Anna is the standard form to use.

Preparo is the first person singular of preparare in the present indicative.

So:

• preparare = to prepare / to make
• io preparo = I prepare / I am preparing / I make

The ending -o tells you the subject is I.

Because Italian often leaves out subject pronouns when they are not needed.

The verb ending already shows who the subject is:

• preparo = I prepare
• prepari = you prepare
• prepara = he/she prepares

So io preparo is possible, but just preparo is more natural unless you want emphasis or contrast.

For example:

• Io preparo una torta, tu porti il vino. = I’ll make a cake, you bring the wine.

Here io is used for contrast.

Yes. In Italian, the present tense is often used for:

• actions happening now
• habitual actions
• planned or near-future actions
• statements in a general context

So preparo una torta can mean:

• I’m making a cake
• I make a cake
• I’m going to make a cake
• I make a cake for Anna’s birthday

The exact meaning depends on context. Italian uses the present more broadly than English sometimes does.

Una torta uses the indefinite article, meaning a cake.

That is used when the cake is being mentioned as one item, not as a specific already-known cake.

• preparo una torta = I make a cake
• preparo la torta = I make the cake

You would use la torta if both speaker and listener already know which cake is meant.

Because torta is a feminine singular noun.

• una torta
• la torta

In Italian:

• masculine singular indefinite article: un / uno
• feminine singular indefinite article: una

Examples:

• un libro = a book
• uno studente = a student
• una torta = a cake

Yes. Italian word order is fairly flexible, especially with introductory phrases.

These are all possible:

• In occasione del compleanno di Anna, preparo una torta.
• Preparo una torta in occasione del compleanno di Anna.
• Per il compleanno di Anna preparo una torta.

The version with the introductory phrase first gives a nice sense of context before the main action.

The comma is natural when the sentence begins with a longer introductory phrase:

• In occasione del compleanno di Anna, preparo una torta.

It helps readability. In short informal writing, people might omit it, but using it here is a good choice.

So:

• with comma = clearer, more polished
• without comma = still understandable

Yes, absolutely.

• Per il compleanno di Anna, preparo una torta.
• In occasione del compleanno di Anna, preparo una torta.

Both are correct.

The difference is mainly in tone:

• per il compleanno di Anna = more everyday, direct
• in occasione del compleanno di Anna = a bit more formal or elegant

A learner will hear per il compleanno di Anna very often in normal conversation.

Literally, preparare means to prepare, but in many contexts it is the natural Italian verb where English would often say make.

So:

• preparo una torta = I make a cake
• also literally: I prepare a cake

In food contexts, preparare is extremely common and natural.

Di Anna means of Anna and shows possession or association.

In:

• il compleanno di Anna

it means:

• Anna’s birthday
• literally, the birthday of Anna

This is one of the most common ways Italian expresses possession with nouns:

• la casa di Luca = Luca’s house
• il compleanno di Anna = Anna’s birthday

Italian does not normally use an apostrophe-s structure like English does.