Sayari hii ni kubwa.

• sayari = planet
• hii = this
• ni = is
• kubwa = big / large

So the sentence is literally ordered like planet this is big.

In Swahili, demonstratives such as this usually come after the noun they describe.

So:

• sayari hii = this planet
• literally, planet this

That word order is normal in Swahili, even though it feels reversed to an English speaker.

ni is the copula, the word that works like English is / am / are in sentences like this.

It links the subject to a description:

• Sayari hii ni kubwa = This planet is big

A useful thing to know is that ni does not change the way English am / is / are do. It stays ni with different subjects.

sayari belongs to the class 9/10 noun group, often called the N-class.

That matters because words that go with the noun must agree with its class. In this sentence, that affects the demonstrative:

• singular: hii = this
• plural: hizi = these

So:

• sayari hii = this planet
• sayari hizi = these planets

Because sayari is in noun class 9/10, and with that class, adjectives often appear with no extra visible agreement prefix.

So kubwa stays kubwa.

Compare that with other noun classes, where the adjective does change:

• mtoto mkubwa = big child
• watoto wakubwa = big children
• kitabu kikubwa = big book
• vitabu vikubwa = big books

But with sayari, kubwa is correct as it is.

You would say:

Sayari hizi ni kubwa.

Notice what changes:

• sayari stays the same
• hii changes to hizi
• ni stays ni
• kubwa stays kubwa

This is very common with class 9/10 nouns: the noun itself often looks the same in singular and plural, and the agreement words show the number.

No. Swahili does not use articles the way English does.

So there is no separate word matching a, an, or the here.

Instead, definiteness is usually understood from:

• context
• demonstratives like hii = this
• other modifiers

Because this sentence has hii, it is already very specific: this planet.

For a learner, the best pattern to use is sayari hii.

Standard basic Swahili normally puts the demonstrative after the noun:

• sayari hii

So if you want to say this planet, use sayari hii.

They are different sentences.

• Sayari hii ni kubwa = This planet is big
• Hii ni sayari kubwa = This is a big planet

In the first sentence, sayari hii is the subject: this planet.

In the second sentence, hii means this by itself, and sayari kubwa means a big planet.

hii is pronounced with two vowel sounds, roughly hee-ee.

So the whole sentence is approximately:

sa-YA-ri hee-ee nee KOO-bwa

A few helpful pronunciation notes:

• Swahili vowels are usually clear and steady
• hii is not pronounced like English hi
• kubwa has two clear parts: ku-bwa