Appena finisce la lezione, gli studenti si mettono a parlare in cortile.

Yes, appena often means just in sentences like Ho appena mangiato = I just ate.

But in this sentence, appena means as soon as:

• Appena finisce la lezione = As soon as the lesson/class ends

So appena has more than one common use, and the meaning depends on the context.

Italian very often uses the present tense where English might use the present or the future, especially in time clauses introduced by words like:

• quando = when
• appena = as soon as
• dopo che = after

So:

• Appena finisce la lezione, gli studenti...

is completely natural Italian, even if in English we think of it as something that happens next.

This present tense can describe:

• a habitual action: Whenever class ends...
• a future sequence: As soon as class ends...

Italian does not normally say Appena finirà la lezione in this kind of everyday structure.

The subject is la lezione.

Italian often places the verb before the subject, especially in clauses like this:

• finisce la lezione = the lesson ends

This word order is very natural after appena.

You could also understand it as:

• Appena la lezione finisce...

but Appena finisce la lezione... sounds more natural here.

Because studenti begins with st-, and in Italian masculine plural nouns beginning with certain sounds take gli, not i.

Use gli before masculine plural nouns starting with:

• s + consonant: gli studenti
• z: gli zii
• gn: gli gnocchi
• ps: gli psicologi
• x or y in many cases

So:

• singular: lo studente
• plural: gli studenti

No. Here gli is the definite article, meaning the.

So:

• gli studenti = the students

This is different from the pronoun gli, as in:

• Gli parlo = I speak to him
• Gli parlo spesso = I speak to him often

Same word, different grammar role.

Mettersi a + infinitive is a very common expression meaning:

• to start
• to begin
• to set about doing something

So:

• si mettono a parlare = they start talking
• literally, something like they put themselves to talking

But you should learn it as a fixed expression:

• mettersi a ridere = to start laughing
• mettersi a piangere = to start crying
• mettersi a studiare = to start studying

Because the verb here is mettersi, not just mettere.

• mettere = to put
• mettersi a + infinitive = to begin doing something

In this expression, the reflexive form is part of the idiom. So you should think of mettersi a parlare as a single pattern meaning to start talking.

In this sentence:

• si mettono = they begin

The si matches gli studenti.

Yes, absolutely.

• Gli studenti si mettono a parlare in cortile
• Gli studenti cominciano a parlare in cortile

Both are correct.

There is a slight nuance:

• cominciare a parlare = neutral begin to talk
• mettersi a parlare = often a bit more vivid, like they get talking / they start talking

So mettersi a can sometimes sound a little more dynamic.

Because after mettersi, Italian uses the pattern:

• mettersi a + infinitive

So:

• si mettono a parlare = they start talking

The form parlando is a gerund, meaning something like talking in the sense of while talking, and it does not fit after mettersi in this structure.

Correct:

• si mettono a parlare

Not correct here:

• si mettono parlando

In cortile means in the courtyard / out in the courtyard.

Both in cortile and nel cortile can exist, but they are not always used in exactly the same way.

• in cortile often sounds more general, like out in the courtyard area
• nel cortile can sound a bit more specific: in the courtyard, referring to a particular one more explicitly

In a school context, in cortile is very natural.

It can be either, depending on context.

• la lezione finisce can mean the lesson ends
• in a school context, it can also be understood as class ends

So English may translate it differently depending on what sounds most natural.

Italian uses articles more often than English.

So where English says:

• class ends

Italian often says:

• finisce la lezione

This is normal and does not sound overly specific in Italian.

It can naturally suggest a habitual action:

• As soon as class ends, the students start talking in the courtyard.

That sounds like something that typically happens.

But depending on context, it could also describe a single scene in a vivid, present-tense way.

Italian present tense is flexible like that.

Because after appena in a time clause like this, Italian normally uses the indicative:

• Appena finisce la lezione...

This is the normal pattern for real, expected events in time clauses.

So finisce is exactly what you would expect here.

Yes.

• Appena finisce la lezione...
• Non appena finisce la lezione...

Both mean as soon as the lesson ends.

Non appena is a bit more formal or emphatic, while appena is very common and natural in everyday Italian.

Here gli is pronounced like the normal article gli, but because it comes before studenti, in connected speech it may sound quick and light.

A useful thing to remember is that article gli is not pronounced like English glee.

The gl sound in Italian is special, similar to the sound in famiglia. But before another word, learners often just need to recognize it comfortably rather than over-focus on it.

So:

• gli studenti

may feel tricky at first, but it becomes easier with repetition. The important thing is to recognize it as the plural article for lo studente.

Not in natural English.

That is closer to the literal structure, but the real meaning is simply:

• they start talking
• they begin talking
• they get talking

When learning Italian, it is helpful to notice the literal pieces, but for understanding and translation, treat mettersi a + infinitive as a set expression.