Se una sillaba è difficile, la maestra la ripete con calma.

Se means if.

In this sentence, it introduces a condition:

• Se una sillaba è difficile = If a syllable is difficult

This is a very common pattern in Italian, just like in English:

• Se piove, resto a casa. = If it rains, I stay home.
• Se ho tempo, ti chiamo. = If I have time, I call you / I’ll call you.

Here, the sentence describes a general or repeated situation, so the present tense is used in both parts.

Italian usually uses an article where English often can omit one.

• una sillaba = a syllable

The noun sillaba is feminine singular, so it takes the feminine singular indefinite article una.

Compare:

• un libro = a book
• una parola = a word
• una sillaba = a syllable

So una is there because Italian normally needs the article with countable singular nouns in a sentence like this.

È is the verb is from essere.

The accent matters because it distinguishes è from e:

• è = is
• e = and

So:

• la sillaba è difficile = the syllable is difficult
• la sillaba e la parola would mean the syllable and the word

This is an important spelling point in Italian.

Some Italian adjectives have the same form for masculine and feminine in the singular. Difficile is one of them.

So you get:

• un libro difficile = a difficult book
• una sillaba difficile = a difficult syllable

But in the plural, it changes to difficili:

• libri difficili
• sillabe difficili

So the adjective does agree with the noun, but the masculine singular and feminine singular happen to look the same here.

They do two different jobs.

1. la maestra
   Here la is the definite article: the teacher

2. la ripete
   Here la is a direct object pronoun: it

That pronoun refers back to una sillaba. Since sillaba is feminine singular, the pronoun is la.

So:

• la maestra = the teacher
• la ripete = repeats it

Literally, the sentence structure is:

• If a syllable is difficult, the teacher repeats it calmly.

Italian often uses object pronouns before the verb:

• La ripete = She repeats it

You could also say:

• La maestra ripete la sillaba con calma.

That is also correct, but using la avoids repeating the noun.

In Italian, unstressed direct object pronouns usually come before a conjugated verb.

So:

• La ripete = She repeats it
• Lo vedo = I see him/it
• Ti chiamo = I call you

This is different from English, where the object usually comes after the verb:

• She repeats it

In Italian, with a normal finite verb, pronouns like lo, la, li, le usually go before the verb.

Ripetere is the infinitive, meaning to repeat.
Ripete is the conjugated form, meaning he/she repeats.

Since the subject is la maestra (the teacher), the verb must be third person singular:

• io ripeto = I repeat
• tu ripeti = you repeat
• lui/lei ripete = he/she repeats
• noi ripetiamo = we repeat
• voi ripetete = you all repeat
• loro ripetono = they repeat

So:

• la maestra la ripete = the teacher repeats it

Most naturally, it sounds like a general habit or a usual action.

• Se una sillaba è difficile, la maestra la ripete con calma.

This means something like:

• If a syllable is difficult, the teacher repeats it calmly.

That is a general statement: whenever that situation happens, this is what the teacher does.

Italian often uses the present tense for this kind of general truth or repeated action, just as English can do.

Con calma literally means with calmness, but in natural English it usually means:

• calmly
• slowly and patiently
• without rushing

So here it suggests that the teacher repeats the syllable in a patient, unhurried way.

Italian often uses con + noun where English might prefer an adverb:

• con attenzione = carefully
• con pazienza = patiently
• con calma = calmly

You could also say calmamente, but con calma is very common and natural.

The comma separates the if-clause from the main clause:

• Se una sillaba è difficile, = subordinate clause
• la maestra la ripete con calma. = main clause

This is very common when the conditional part comes first.

Italian punctuation here works much like English:

• If a syllable is difficult, the teacher repeats it calmly.

Yes. You could also put the main clause first:

• La maestra la ripete con calma se una sillaba è difficile.

This is grammatically correct, though the original version is often more natural because it introduces the condition first.

The original sentence puts emphasis on the situation:

• If a syllable is difficult...

Then it tells you what happens:

• ...the teacher repeats it calmly.