Ni vizuri kuonyesha usikivu tunapojifunza darasani.

Ni vizuri means It is good or It is a good thing.

• ni = is / it is
• vizuri = good / well, depending on context

In sentences like this, Swahili often uses an impersonal expression. English usually supplies it, but Swahili does not need a separate word for that idea here.

Kuonyesha is the infinitive form, meaning to show.

The structure Ni vizuri + infinitive is very common in Swahili and means It is good to...

So:

• Ni vizuri kuonyesha... = It is good to show...

The ku- at the beginning is the marker for the infinitive, like English to in to show.

Usikivu means something like attentiveness, listening, or attention.

It comes from the idea of hearing/listening:

• kusikia = to hear
• usikivu = the quality of listening / attentiveness

In a classroom sentence like this, usikivu is best understood as paying attention or being attentive.

Yes. Literally, kuonyesha usikivu means to show attentiveness, but in natural English it often matches to pay attention or to be attentive.

So although the wording is different from English, the idea is very natural in Swahili.

Tunapojifunza can be broken down like this:

• tu- = we
• -na- = present tense
• -po- = when / at the time when
• jifunza = learn / study

So tunapojifunza means when we are learning or as we learn.

This is a very useful Swahili pattern for time clauses.

Here, -po- helps express when or at the time when.

That is why:

• tunajifunza = we are learning
• tunapojifunza = when we are learning

So -po- adds the sense of a time setting inside the verb.

Because -funza and jifunza are different verbs:

• kufunza = to teach
• kujifunza = to learn

Historically, ji- is a reflexive element, so jifunza is like teach oneself, which developed into the normal meaning learn. In modern Swahili, learners usually just memorize:

• kufundisha / kufunza = teach
• kujifunza = learn

Darasani means in the classroom or in class.

It comes from:

• darasa = class / classroom
• -ni = a locative ending, often meaning in, at, or to

So:

• darasa = classroom / class
• darasani = in the classroom / in class

This -ni ending is very common in Swahili place expressions.

A fairly literal breakdown is:

• Ni vizuri = It is good
• kuonyesha = to show
• usikivu = attentiveness / attention
• tunapojifunza = when we are learning
• darasani = in class

So the full sense is:

It is good to show attentiveness when we are learning in class.

In natural English, you might also say:

It is good to pay attention when we are learning in class.