Ninahitaji pesa kidogo kwa ajili ya nauli.

It is made of three parts:

• ni- = I
• -na- = present tense marker
• -hitaji = need

So ninahitaji literally means I need or I am needing.

In Swahili, the subject is usually built into the verb. The ni- in ninahitaji already means I, so you do not need a separate pronoun.

You could add mimi for emphasis:

• Mimi ninahitaji pesa kidogo... = I need a little money...

But in normal speech, the verb alone is enough.

In Swahili, modifiers usually come after the noun they describe.

So:

• pesa kidogo = a little money
• literally, something like money little

This is normal Swahili word order.

Here it means a little money, meaning a small amount of money.

Because pesa is being treated as a mass noun, kidogo refers to quantity, not physical size. So the phrase is about how much money is needed, not about physically small coins or notes.

Swahili does not use articles the way English does. There is no direct equivalent of a or the in most sentences.

In this sentence, kidogo already gives the sense of an indefinite amount, so pesa kidogo naturally conveys a little money or some money.

Kwa ajili ya means for, for the sake of, or for the purpose of.

In this sentence, it shows what the money is needed for:

• kwa ajili ya nauli = for the fare

It is a clear and common way to express purpose. It can sound a little more explicit or slightly more formal than a shorter alternative.

Nauli means fare: the money you pay for transport.

Depending on context, it could mean things like:

• bus fare
• taxi fare
• boat fare
• transport charge

So it does not just mean travel in general; it specifically refers to the price of transportation.

Pesa often behaves like a mass noun, similar to money in English. In this sentence, it is best understood that way.

So the important idea is not singular versus plural, but amount:

• pesa kidogo = a little money

Also, many Swahili loanwords do not show a visible singular/plural change in the same way as other nouns.

No. It is a good, natural choice, but not the only possible one.

A shorter everyday version you may hear is:

• Ninahitaji pesa kidogo kwa nauli.

That still means I need a little money for the fare.
The version with kwa ajili ya is just a bit fuller and more explicit.

A simple syllable breakdown is:

• ni-na-hi-ta-ji
• pe-sa
• ki-do-go
• kwa a-ji-li ya
• nau-li

Swahili words are usually stressed on the second-to-last syllable of each word. So you would roughly hear:

• ninaHItaji
• PEsa
• kiDOgo
• aJIli
• naUli

The pronunciation is generally very regular, so once you know the spelling, it is usually easy to say.