La professora explica per què l'examen és important.

Yes. La professora means the female teacher.

In Catalan, many nouns for people change ending to match gender:

• el professor = the male teacher
• la professora = the female teacher

The article also changes:

• el = masculine singular
• la = feminine singular

So La professora clearly refers to a woman.

Catalan often drops the vowel of the article before a word that begins with a vowel sound.

Here:

• el examen would sound awkward
• so it becomes l'examen

This is very common in Catalan:

• l'amic = the friend
• l'escola = the school
• l'hotel = the hotel

So l' here is just the article el shortened before examen.

Because examen is a masculine noun in Catalan.

So the correct article is:

• el examen
• before a vowel: l'examen

Even though l' does not visibly show gender by itself, the noun is still masculine.

A learner often has to memorize the gender of nouns individually.

Here per què means why or more literally for what reason.

It is written as two words in this use:

• per què = why / for what reason

Example:

• Explica per què l'examen és important. = She explains why the exam is important.

This is different from some similar-looking forms in Catalan, such as:

• perquè = because
• per què = why / for what reason
• per a què = for what purpose
• el perquè = the reason / the motive

So in your sentence, per què introduces an indirect question: why the exam is important.

The accent helps distinguish què from other forms and also marks the stressed vowel.

In this sentence, què is part of per què = why.

Catalan uses accents more consistently than English to show pronunciation and sometimes to distinguish meanings. So the accent in què is not optional here.

This word order is normal in Catalan.

The sentence breaks down like this:

• La professora = the teacher
• explica = explains
• per què l'examen és important = why the exam is important

Just like in English, after explains, Catalan can introduce a clause:

• She explains why the exam is important.

Inside that clause, Catalan keeps the normal statement order:

• l'examen és important = the exam is important

It does not invert the verb the way English sometimes does in direct questions. This is because it is an embedded or indirect question, not a direct one.

Explica is the third person singular present tense of explicar = to explain.

So it can mean:

• he explains
• she explains
• it explains
• you explain (formal singular, depending on context)

Here, because the subject is La professora, it means:

• The teacher explains

Some present-tense forms of explicar are:

• jo explico = I explain
• tu expliques = you explain
• ell/ella explica = he/she explains
• nosaltres expliquem = we explain
• vosaltres expliqueu = you all explain
• ells/elles expliquen = they explain

És is the third person singular present tense of ser = to be.

So:

• l'examen és important = the exam is important

The accent is important here too. És with an accent means is.

Examples:

• És difícil = It is difficult
• És important = It is important

Catalan shares many words with English through Latin or French influence, so some vocabulary looks familiar.

Important is one of those words:

• important in Catalan
• important in English

But even if it looks the same, remember that pronunciation will be Catalan, not English.

Also, adjectives in Catalan often agree with the noun, but important has the same form for masculine and feminine singular:

• un examen important
• una raó important

A rough pronunciation for an English speaker is:

lah proh-fuh-SOH-ruh eks-PLI-kuh per KEH leks-ah-MEN ez im-por-TANT

A few helpful notes:

• ll in professora is just a normal l here, because there is only one l
• x in explica sounds like ks
• què sounds roughly like keh
• és sounds like ez
• final -nt in important is pronounced

This is only an approximation, but it can help you get started.

Yes, in some contexts Catalan can omit the subject if it is already understood, because the verb form often gives enough information.

So you could say:

• Explica per què l'examen és important.

Depending on context, that could mean:

• She explains why the exam is important
• He explains why the exam is important
• You explain why the exam is important (formal)

But with La professora, the subject is explicit and unambiguous.

No. It contains an indirect question.

A direct question would be something like:

• Per què és important l'examen? = Why is the exam important?

Your sentence is not asking that question directly. It is reporting or explaining it:

• La professora explica per què l'examen és important.

So even though per què means why, the whole sentence is a statement, not a question.

Not if you mean explains why.

You need:

• per què = why

If you write perquè, that usually means because.

So these are different:

• explica per què l'examen és important = explains why the exam is important
• explica perquè l'examen és important = explains because the exam is important

The second one is usually not what you want here. So in this sentence, per què is the correct form.