Il segretario controlla il fascicolo prima di inviarlo via email.

Yes. Il segretario means the secretary.

• il = the masculine singular definite article
• segretario = secretary

So il segretario is a specific secretary, not just a secretary.
If it were indefinite, you would usually say un segretario.

Because controlla is a conjugated verb, while controllare is the infinitive.

Here the subject is il segretario, which is third-person singular, so the verb must match:

• controllare = to check
• controlla = he/she checks

So:

• Il segretario controlla... = The secretary checks...

Fascicolo usually means a file, folder, dossier, or case file, depending on context.

It often refers to a set of documents collected together, especially in office, legal, or administrative contexts.
So it is not just any random paper; it suggests an organized file of documents.

For the same reason as in il segretario: it is the masculine singular definite article meaning the.

• il segretario = the secretary
• il fascicolo = the file / dossier

Italian usually uses articles more consistently than English, so seeing il twice in one sentence is completely normal.

Prima di means before when it is followed by an infinitive.

Structure:

• prima di + infinitive

So:

• prima di inviarlo = before sending it

Compare:

• prima di partire = before leaving
• prima di mangiare = before eating

If a full clause follows instead of an infinitive, Italian often uses prima che:

• prima che parta = before he/she leaves

Because -lo means it, and it refers back to il fascicolo.

• inviare = to send
• inviarlo = to send it

Italian often attaches object pronouns directly to an infinitive:

• farlo = to do it
• vederlo = to see it
• mandarlo = to send it

So prima di inviarlo literally means before to-send-it, which in natural English is before sending it.

Because lo refers to il fascicolo, which is a masculine singular noun.

Direct object pronouns must agree with the noun they replace in gender and number:

• lo = him / it (masculine singular)
• la = her / it (feminine singular)
• li = them (masculine plural)
• le = them (feminine plural)

Since fascicolo is masculine singular, the correct pronoun is lo.

Yes, absolutely.

Both are correct:

• prima di inviare il fascicolo
• prima di inviarlo

The version with inviarlo avoids repeating il fascicolo and sounds more natural once the object has already been mentioned.

Via email means by email or via email.

Yes, this is very common in modern Italian.
Via is often used to show the means by which something is sent or done:

• via email = by email
• via internet = via the internet
• via posta = by post/mail

You may also see per email, but via email is extremely common.

Because Italian is a pro-drop language: the subject pronoun is often omitted when the verb form already makes the subject clear.

So instead of saying:

• Lui controlla il fascicolo...

Italian normally just says:

• Controlla il fascicolo...

In this sentence, the noun il segretario is already present, so a pronoun would be unnecessary.

Yes, but it is also very natural and standard.

The basic structure is:

• Il segretario = subject
• controlla = verb
• il fascicolo = object
• prima di inviarlo via email = time/action phrase

So the sentence flows as:

subject + verb + object + before + infinitive phrase

This is a very normal Italian word order.
Italian can sometimes be flexible, but this version is the most straightforward and neutral.

Inviare ends in -are, but when you attach a pronoun to the infinitive, the final -e drops:

• inviare + lo → inviarlo

This is a normal rule with infinitives + attached pronouns:

• fare + lo → farlo
• vedere + la → vederla
• dire + gli → dirgli

So inviarlo is not irregular; it is just the standard form created from inviare + lo.

In this sentence, controllare means to check, not to control.

This is an important false-friend point:

• Italian controllare = to check, inspect, verify
• English to control usually means to direct, manage, or keep under control

So here Il segretario controlla il fascicolo means the secretary is checking/reviewing the file, not controlling it.