L'ispettore controlla il documento.

Because ispettore begins with a vowel sound, the masculine singular definite article becomes l'.

So:

• il libro
• il documento
• l'ispettore
• l'amico

The apostrophe shows that the vowel of the article has been dropped. In natural Italian, you do not say il ispettore.

Ispettore is masculine singular here.

• l'ispettore = the male inspector / the inspector
• l'ispettrice = the female inspector

So the sentence specifically uses the masculine form of the noun.

Here is the structure:

• L'ispettore = the subject
• controlla = the verb
• il documento = the direct object

So this is a very standard subject + verb + object sentence.

Controlla is the third-person singular present indicative of controllare.

Conjugation in the present:

• io controllo = I check
• tu controlli = you check
• lui/lei controlla = he/she checks
• noi controlliamo = we check
• voi controllate = you all check
• loro controllano = they check

So controlla matches a singular subject such as l'ispettore.

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

Here, the subject is already clearly stated as l'ispettore, so adding lui would be unnecessary in most cases.

• L'ispettore controlla il documento. = normal
• Lui controlla il documento. = possible, but usually used for emphasis or contrast

Italian does this much more often than English.

Often, controllare means to check, to inspect, or to examine. This is a very common point for English speakers because it can look like the English verb control.

In many contexts:

• controllare un documento = to check a document
• controllare i biglietti = to check tickets

Sometimes controllare can mean to control, but very often in everyday Italian it means to check. So it is a word to be careful with.

Il is the definite article, meaning the.
Un would be the indefinite article, meaning a or an.

So:

• il documento = the document
• un documento = a document

Using il documento suggests a specific document, not just any document.

Because documento is:

• masculine
• singular
• beginning with a consonant

For this kind of noun, the normal definite article is il.

Examples:

• il libro
• il tavolo
• il documento

So il documento follows the regular pattern.

Because documento is the direct object of controllare, and direct objects in Italian normally do not take a preposition.

So:

• controllare il documento = to check the document

This is similar to English, where you also say check the document, not check to the document.

This sentence uses the most neutral and common word order:

• Subject + Verb + Object

So:

• L'ispettore controlla il documento.

Italian can change word order for emphasis, but this is the standard version. For a beginner, this is the safest pattern to learn first.

Yes. The Italian present tense can often correspond to either:

• checks
• is checking

depending on context.

So L'ispettore controlla il documento could mean either:

• The inspector checks the document
• The inspector is checking the document

If you want to strongly emphasize that the action is happening right now, Italian can also use:

• L'ispettore sta controllando il documento.

A helpful pronunciation guide is:

lis-pet-TOR-e con-TROL-la il do-cu-MEN-to

A few useful notes:

• ispettore has the stress on -to-
• controlla has the stress on -trol-
• documento has the stress on -men-
• the double consonants in ispettore and controlla are pronounced more strongly than single consonants

The article l' connects directly to ispettore, so you say it as one unit: l'ispettore.

You could pluralize the subject, the object, or both.

Examples:

• Gli ispettori controllano il documento. = The inspectors check the document.
• L'ispettore controlla i documenti. = The inspector checks the documents.
• Gli ispettori controllano i documenti. = The inspectors check the documents.

Notice the changes:

• l'ispettore → gli ispettori
• controlla → controllano
• il documento → i documenti