Aprender a conducir de noche también fue un reto para mi prima.

Because the whole phrase Aprender a conducir de noche functions as the subject of the sentence.

In English, we do something similar with Learning to drive at night. In Spanish, an infinitive can act like a noun or noun phrase, so aprender here means learning.

That is also why the verb later is singular: fue. The whole action is treated as one single thing.

After aprender, Spanish normally uses a + infinitive when you mean learn to do something.

So:

• aprender a conducir = to learn to drive
• aprender a nadar = to learn to swim
• aprender a cocinar = to learn to cook

The a is the normal pattern here.

Yes. In Spain, conducir is the standard and very natural verb for to drive a vehicle.

So:

• conducir un coche = to drive a car

You may also hear manejar in many Latin American countries, but in Spain conducir is the usual choice.

Yes, both are possible, but they are not exactly the same in feeling.

• de noche often emphasizes when it is dark / at night-time
• por la noche often means in the evening / at night as a time period

In this sentence, de noche sounds especially natural because the difficulty is connected to driving in darkness.

So Aprender a conducir de noche suggests learning to drive under night-time conditions.

También means also or too.

Here it is placed before fue, which is a very natural position in Spanish:

• Aprender a conducir de noche también fue un reto...

This means that learning to drive at night was also a challenge, probably in addition to other challenges already mentioned.

Spanish adverbs like también can sometimes move around, but this position is very normal and clear.

Fue is the preterite form of ser, and here it presents the challenge as a completed fact.

So fue un reto means something like:

• it turned out to be a challenge
• it was a challenge

If you said era un reto, it would sound more descriptive or ongoing, as if you were describing the situation in the background rather than viewing it as a whole.

In this sentence, fue is the more natural choice.

Because reto is a countable noun, and in this sentence Spanish normally needs the article.

So:

• fue un reto = it was a challenge

Without un, the sentence would sound incomplete or unnatural in standard Spanish.

Reto means challenge.

It is close to difficulty, but not exactly the same:

• reto = something demanding that requires effort
• dificultad = difficulty
• problema = problem

So un reto often has a slightly more positive or neutral tone than un problema. It suggests something hard, but not necessarily bad.

Para mi prima means for my cousin or to my cousin / as far as my cousin was concerned, depending on how you think about it.

Here, para marks the person affected by the situation:

• fue un reto para mi prima = it was a challenge for my cousin

As for the spelling:

• mi without an accent = my
• mí with an accent = me

So:

• mi prima = my cousin
• para mí = for me

In this sentence, mi is a possessive adjective modifying prima, so it does not take an accent.

Yes. Spanish normally marks the gender of family words like this:

• primo = male cousin
• prima = female cousin

So mi prima tells you that the cousin is female.

Unlike English cousin, Spanish usually requires you to choose the masculine or feminine form.

Yes. Spanish word order is more flexible than English.

For example, you could also say:

• También fue un reto para mi prima aprender a conducir de noche.

That version is also correct and natural. The original sentence simply puts the action Aprender a conducir de noche first, which makes that idea the main topic.

Because the stress falls on the final syllable: tam-bién.

In Spanish spelling, words ending in n, s, or a vowel usually have stress on the second-to-last syllable unless an accent mark shows otherwise. The written accent in también tells you that the stress is on -bién.

So it is pronounced roughly tam-BYEN.