Kalamu zile ziko kwenye droo.

In Swahili, demonstratives like this/that/these/those usually come after the noun, not before it.

So:

• kalamu zile = those pens
• literally: pens those

Also, zile must agree with the noun class of kalamu here. Since the sentence is talking about plural pens, the plural agreement is used.

Some Swahili nouns have the same form in singular and plural, and kalamu is one of them.

So:

• kalamu can mean pen
• kalamu can also mean pens

You know whether it is singular or plural from the words that agree with it:

• kalamu ile = that pen
• kalamu zile = those pens

In your sentence, zile and ziko show that kalamu is plural.

Zile means those for this noun class in the plural.

A useful comparison:

• ile = that / that one with singular kalamu
• zile = those with plural kalamu

So:

• kalamu ile = that pen
• kalamu zile = those pens

Ziko means something like they are there / they are located.

In this sentence, it is used to say where the pens are:

• kalamu zile ziko kwenye droo = those pens are in the drawer

The zi- part is the agreement prefix for the plural noun class of kalamu here.

So ziko is not just a random word—it matches kalamu zile.

Swahili often uses forms like yuko, wako, kiko, viko, ziko when talking about location or existence.

So for location, you say:

• Kalamu zile ziko kwenye droo = Those pens are in the drawer.

You would not normally use ni here.

Very roughly:

• ni is often used for identification: X is Y
• -ko forms like ziko are often used for location: X is in/at Y

Kwenye means in, on, at, onto, depending on context. It is a very common location word.

In this sentence:

• kwenye droo = in the drawer

So kwenye is introducing the location where the pens are.

Droo means drawer. It is a borrowed word, but it is completely normal in everyday Swahili.

So:

• kwenye droo = in the drawer

Learners should know that Swahili uses many borrowed words, especially for modern or household objects.

Swahili does not have articles like a, an, or the.

So droo can mean:

• a drawer
• the drawer

The exact meaning depends on context. In your sentence, English naturally translates it as the drawer, but Swahili does not need a separate word for the.

We know it is plural because of the agreement words:

• zile = those (plural)
• ziko = they are there / they are located (plural agreement)

Even though kalamu itself does not change form, the agreeing words show the number clearly.

Not usually in this kind of basic sentence.

Swahili normally keeps the noun phrase together like this:

• kalamu zile = those pens

Then it adds the location statement:

• ziko kwenye droo

So the full sentence structure is:

• [noun + demonstrative] + [location verb] + [place]

That is why Kalamu zile ziko kwenye droo sounds natural.