Molekuli hii ni ndogo.

In Swahili, demonstratives like this usually come after the noun.

So:

• molekuli hii = this molecule
• literally: molecule this

That is normal Swahili word order. English says this molecule, but Swahili typically says molecule this.

Ni is the usual Swahili word for is / are when linking a subject to a description or identity.

So in:

• Molekuli hii ni ndogo

ni connects molekuli hii and ndogo, just like is in English:

• This molecule is small

It is a very common copula-like word in Swahili.

Yes. Ndogo means small.

The basic adjective stem is often given as -dogo, but in actual sentences it usually appears with agreement based on the noun class. With molekuli, the correct form here is ndogo.

So:

• -dogo = adjective stem
• ndogo = the form used here, meaning small

They often do, and that is exactly what is happening here.

Molekuli belongs to the N class (often called class 9/10). Many nouns in this class use adjective forms like ndogo, kubwa, nzuri, etc.

So the adjective is agreeing with the noun, but for this class the agreement form may look very similar to what learners already see in dictionaries.

That means:

• molekuli ndogo = small molecule
• molekuli hii ni ndogo = this molecule is small

Swahili does not normally use articles like English a and the.

So molekuli can mean:

• a molecule
• the molecule
• just molecule

The context tells you which meaning is intended. In this sentence, hii makes it specific:

• molekuli hii = this molecule

It is a borrowed word, ultimately related to the international word molecule.

Swahili has many loanwords, especially for science, technology, religion, and modern life. Molekuli is completely normal Swahili vocabulary for scientific use.

A simple guide:

• molekuli ≈ mo-le-KU-li
• hii ≈ hee-ee
  
  • The two i sounds are both pronounced, so it is not just English he
• ni ≈ nee
• ndogo ≈ n-DO-go

A useful pronunciation point: in ndogo, the n is really pronounced. It begins with an nd sound, not just dogo.

In standard Swahili, for a sentence like This molecule is small, you normally use ni:

• Molekuli hii ni ndogo

Without ni, the sentence would not be the normal basic form for most learners to use. It may sound incomplete or nonstandard in this context.

So as a beginner, it is safest to keep ni here.

You would change both the demonstrative and the noun meaning to plural:

• Molekuli hizi ni ndogo.

Breakdown:

• molekuli = molecule / molecules
• hizi = these
• ni = are
• ndogo = small

Notice that molekuli stays the same in singular and plural here, which is common for many nouns in this class.

You would change the demonstrative:

• Molekuli ile ni ndogo. = That molecule is small.

So:

• hii = this
• ile = that

The rest of the sentence stays the same.

Sometimes, yes. Like many adjectives, -dogo can be used in slightly different ways depending on context.

It can mean:

• small
• little
• sometimes younger in certain expressions

But in a scientific sentence with molekuli, the natural meaning is simply small:

• Molekuli hii ni ndogo. = This molecule is small.