Katika somo la jiografia, Rahma alitumia dira, lakini Juma alihitaji kikokotoo kwa hesabu.

In Swahili, a finite verb normally still carries a subject marker, even when the subject noun is explicitly named.

So:

• Rahma alitumia ...
• Juma alihitaji ...

Both verbs use a-, which means he/she for a singular person.

You can break them down like this:

• a-li-tumia

  • a- = he/she
  • -li- = past tense
  • -tumia = use

• a-li-hitaji

  • a- = he/she
  • -li- = past tense
  • -hitaji = need

So even though Rahma and Juma are named, the verb still agrees with them.

-li- is the past tense marker in Swahili.

So:

• alitumia = he/she used
• alihitaji = he/she needed

This pattern is very common:

• nilienda = I went
• ulisoma = you read
• alisema = he/she said
• tulifanya = we did

A very useful formula is:

subject marker + tense marker + verb stem

For example:

• a-li-tumia
• a-li-hitaji

Because the connector meaning of changes according to the noun class of the first noun.

Here, the main noun is somo (lesson/class), and somo belongs to noun class 5 in the singular. Class 5 uses la for this kind of connection.

So:

• somo la jiografia = geography lesson/class

If it were plural, it would become:

• masomo ya jiografia = geography lessons

So the pattern is:

• singular class 5: la
• plural class 6: ya

This is why la is correct here.

Katika usually means in, within, or sometimes during, depending on context.

In this sentence, it introduces the setting:

• Katika somo la jiografia = in/during geography class

It is a very natural way to set the scene, especially in slightly more formal or written Swahili.

In conversation, people might also use something like:

• kwenye somo la jiografia
• katika kipindi cha jiografia

But katika is perfectly standard and clear.

It does not have to come first. Swahili word order is somewhat flexible, especially with time/place/context phrases.

The version given puts the setting first for emphasis:

• Katika somo la jiografia, Rahma alitumia dira...

You could also say:

• Rahma alitumia dira katika somo la jiografia...

Both are grammatical. The difference is mostly about focus:

• Katika somo la jiografia... foregrounds the context
• Rahma alitumia dira... foregrounds the person and action first

Swahili does not have articles like English a/an/the.

So a noun by itself can often mean:

• a compass
• the compass

or

• a calculator
• the calculator

The exact meaning depends on context.

So:

• alitumia dira can mean used a compass or used the compass
• alihitaji kikokotoo can mean needed a calculator or needed the calculator

If Swahili wants to make something more specific, it often uses other tools, such as:

• demonstratives: hiki kikokotoo = this calculator
• possessives: kikokotoo chake = his/her calculator
• context from the surrounding sentence

Here, kwa shows purpose or use.

So kwa hesabu means something like:

• for calculations
• for arithmetic
• for doing sums

In other words, Juma needed the calculator for calculation work.

This use of kwa is very common. It can mean things like:

• for
• by
• with
• at
  depending on context

In this sentence, the idea is clearly for calculations.

If you wanted to make it more explicit, you could also say:

• kwa kufanya hesabu = for doing calculations

But kwa hesabu is shorter and natural.

It can mean either, depending on context.

Hesabu commonly refers to:

• arithmetic
• mathematics
• calculations
• sums

In this sentence, because it comes after kikokotoo, the most natural reading is for calculations or for arithmetic.

If you wanted to say specifically in math class, you would more likely say:

• katika somo la hesabu = in math class

So:

• kwa hesabu = for calculations
• somo la hesabu = math lesson/class

That is an important difference.

Lakini means but.

It connects two contrasting clauses:

• Rahma alitumia dira
• Juma alihitaji kikokotoo kwa hesabu

So the sentence contrasts what Rahma used with what Juma needed.

It works very much like English but.

You will also see it often in the middle of longer sentences:

• Nilitaka kwenda, lakini nilichelewa.
  • I wanted to go, but I was late.

The comma before lakini is common in writing, especially in longer sentences, though punctuation in Swahili can be a little less rigid than in English.

Kikokotoo belongs to noun class 7/8, which often has:

• singular ki-
• plural vi-

So:

• kikokotoo = calculator
• vikokotoo = calculators

This is a very common pattern in Swahili:

• kitabu / vitabu = book / books
• kiti / viti = chair / chairs
• kikokotoo / vikokotoo = calculator / calculators

Knowing noun classes helps with agreement elsewhere in the sentence.

Dira is commonly treated like a noun in the N-class (class 9/10), where the singular and plural are often the same in form.

So it may stay:

• dira = compass
• dira = compasses

Many Swahili nouns in this class do not visibly change in the plural. For learners, the important thing is that not all plurals are made by adding a visible ending the way English often does.

Even when the noun itself stays the same, agreement words elsewhere may show whether it is singular or plural.

Grammatically, it does not matter here. Swahili uses the same singular human subject marker a- for he and she.

So:

• Rahma alitumia = Rahma used
• Juma alihitaji = Juma needed

The verb form does not change based on male vs. female.

This is different from English, where he and she are different words. In Swahili, the same agreement marker works for either one.

Yes. It shows a very common and useful Swahili structure:

context phrase + subject + past-tense verb + object, lakini + subject + past-tense verb + object + purpose phrase

Broken down:

• Katika somo la jiografia = context/setting
• Rahma alitumia dira = first clause
• lakini
• Juma alihitaji kikokotoo kwa hesabu = second clause

This pattern is helpful because you can reuse it easily:

• Katika darasa la sayansi, Asha alitumia darubini, lakini Musa alihitaji daftari.
• Katika mkutano, mwalimu alizungumza, lakini wanafunzi walisikiliza.

So the sentence is not only good for vocabulary; it is also a good model for building your own Swahili sentences.