Wanafunzi wanaokuja mapema darasani wanajifunza vizuri.

Wanafunzi means students. It is a noun in the m-/wa- noun class for people:

• singular: mwanafunzi = student
• plural: wanafunzi = students

Swahili usually does not have a word that directly matches English the or a/an in most ordinary sentences, so wanafunzi can mean students or the students, depending on context.

Wanaokuja is a relative verb form meaning who are coming or, in natural English here, who come.

It can be broken down like this:

• wa- = they / people-class subject agreement
• -na- = present tense
• -o- = relative marker, giving the sense of who / that / which
• -kuja = to come

So wanaokuja literally means something like they-who-are-coming, and it modifies wanafunzi:

• wanafunzi wanaokuja = students who come

Because both verbs agree with wanafunzi, which is a plural noun referring to people.

In Swahili, verbs usually show agreement with the subject. Since wanafunzi is plural and belongs to the people noun class, the subject marker is wa-.

So:

• wanafunzi wanaokuja = students who come
• wanafunzi ... wanajifunza = students ... learn

That repeated wa- is normal and required.

The -o- is the relative marker. It creates the meaning who, that, or which.

Without getting too technical, compare:

• wanakuja = they are coming
• wanaokuja = they who are coming / those who come

In this sentence, it connects the action of coming to the noun wanafunzi:

• wanafunzi wanaokuja mapema = students who come early

Mapema means early. Here it modifies the action come, so it comes after the verb phrase:

• wanaokuja mapema = who come early

That is a very natural placement in Swahili. It works much like an adverb in English, even though word-for-word order does not always match perfectly.

Darasani means in the classroom or to class / at school in class context, depending on context.

It comes from:

• darasa = class / classroom
• -ni = a locative ending, often giving the sense of in, at, to

So darasani is a location word. In this sentence, it tells you where the coming happens:

• wanaokuja mapema darasani = who come early to class / to the classroom

Wanajifunza comes from -jifunza, which means learn.

The ji- here is part of the verb form and gives the idea of learning oneself, which is how Swahili expresses to learn:

• -fundisha = teach
• -jifunza = learn

So:

• wanajifunza = they learn / they are learning

By contrast, wanafundisha would mean they teach, not they learn.

Vizuri means well. It modifies wanajifunza:

• wanajifunza vizuri = they learn well

So the end of the sentence tells us how they learn.

Usually it expresses a general truth or a habitual idea:

• Students who come early to class learn well.

Even though -na- is often called the present tense, in Swahili it can describe:

• what is happening now
• what usually happens
• a general fact

In this sentence, the most natural reading is a general statement.

Grammatically, the Swahili present can sometimes allow that kind of literal translation, but in normal English this sentence is best understood as:

• Students who come early to class learn well.

That is because the sentence sounds like a general observation, not a description of one specific moment.

A helpful way to see it is:

• Wanafunzi = students
• wanaokuja mapema darasani = who come early to class
• wanajifunza vizuri = learn well

So the structure is:

noun + relative clause + main verb

More clearly:

• Wanafunzi
  wanaokuja mapema darasani
  wanajifunza vizuri.

In English:

• Students
  who come early to class
  learn well.

Yes. Depending on context, darasani can be understood in slightly different but closely related ways:

• in class
• in the classroom
• to class

In this sentence, English speakers will often say come early to class, because that sounds most natural. But the Swahili locative is broader than a single English preposition, so darasani does not map to just one exact word every time.