Il contratto stabilisce la regola.

Il is the masculine singular definite article, meaning the.

In il contratto:

• contratto is a masculine singular noun
• so it takes il

Italian articles have to agree with the noun in gender and number.
Here:

• il = masculine singular
• la = feminine singular

So:

• il contratto = the contract
• la regola = the rule

Italian uses articles more often than English does. In this sentence, la regola is the direct object, and Italian normally includes the article.

So:

• la regola = the rule

Leaving out the article would usually sound incomplete or unnatural in a basic sentence like this.

Stabilisce is the third-person singular present tense of stabilire, which means to establish, to set, or to determine, depending on context.

So:

• stabilire = infinitive, to establish
• stabilisce = he/she/it establishes

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

• Il contratto stabilisce... = The contract establishes...

Because stabilire belongs to a group of -ire verbs that add -isc- in some present-tense forms.

For stabilire, the present tense goes like this:

• io stabilisco
• tu stabilisci
• lui/lei stabilisce
• noi stabiliamo
• voi stabilite
• loro stabiliscono

So the -isc- appears in:

• io
• tu
• lui/lei
• loro

but not in:

• noi
• voi

This is very common with certain -ire verbs, such as:

• capire → capisco
• finire → finisce
• preferire → preferiscono

Yes. This sentence follows a very common subject–verb–object order:

• Il contratto = subject
• stabilisce = verb
• la regola = object

So it works much like English:

• The contract / establishes / the rule

Italian can sometimes change word order for emphasis or style, but this version is the most neutral and straightforward.

Italian usually does not use subject pronouns unless they are needed for emphasis, contrast, or clarity.

So instead of saying something like:

• Esso stabilisce la regola

Italian normally just says:

• Il contratto stabilisce la regola

The noun il contratto already tells you the subject, and the verb form stabilisce matches it.

Also, esso exists but is much less common in everyday Italian than it is in English.

You can tell from the sentence structure and the verb.

• Il contratto comes before the verb and functions as the thing doing the action
• la regola comes after the verb and receives the action

So:

• the contract does the establishing
• the rule is what gets established

This is the normal pattern in Italian when there is no special emphasis.

Because regola is a feminine noun in Italian. Noun gender is a grammatical category, and it does not always match biological sex or any logical rule from English.

Here:

• regola is feminine singular
• so it takes la

A lot of Italian nouns ending in -a are feminine, and regola follows that common pattern.

Yes. Depending on context, stabilire can mean:

• to establish
• to set
• to determine
• to lay down

So Il contratto stabilisce la regola could, in another context, be understood as something like:

• The contract sets the rule
• The contract lays down the rule
• The contract determines the rule

The exact English choice depends on the legal or general context.

A simple pronunciation guide is:

eel kon-TRAT-to sta-bee-LEE-she la RE-go-la

A few helpful notes:

• Il sounds roughly like eel
• contratto has the stress on -trat-
• stabilisce has the stress on -li-
• sce in stabilisce sounds like she
• regola has the stress on re-

If you want to sound more natural, try to link the words smoothly: Ilcontratto stabilisce laregola

Possibly, yes, but the nuance may change.

• stabilisce often suggests establishes, lays down, or sets
• determina often suggests determines or decides

In some contexts they may be close, but stabilisce is a very natural choice if the idea is that the contract formally sets out the rule.

So determina is not always wrong, but stabilisce often sounds more appropriate in formal or legal wording.