Shimo hili ni refu.

In Swahili, words like this, that, adjectives, and some verbs often have to agree with the noun class of the noun they go with.

Shimo belongs to noun class 5 in the singular, so the correct this form is hili.

So:

• shimo hili = this hole
• plural: mashimo haya = these holes

English uses the same this for almost everything, but Swahili changes the form depending on the noun class.

Shimo is a class 5 singular noun. Its plural is mashimo, which is class 6.

A useful way to recognize this pair is:

• singular: shimo
• plural: mashimo

Many class 5/6 nouns behave like this: the singular may have no obvious prefix, while the plural often begins with ma-.

This matters because other words in the sentence must match that class:

• shimo hili
• shimo refu
• mashimo haya
• mashimo marefu

In Swahili, modifiers such as demonstratives usually come after the noun.

So the normal order is:

• shimo hili = this hole

not usually the English-style order this hole.

This is a very common pattern in Swahili:

• mtoto huyu = this child
• kitabu hiki = this book
• shimo hili = this hole

So the word order may feel reversed to an English speaker, but it is normal in Swahili.

Ni here is the copula, the word that works like is / are in English.

So:

• Shimo hili ni refu = This hole is deep/long

It links the subject shimo hili with the description refu.

A simple way to think about it is:

• X ni Y = X is Y

For example:

• Kitabu hiki ni kizuri = This book is good.
• Mti huu ni mrefu = This tree is tall.

Because adjectives in Swahili also agree with noun class.

The adjective stem is -refu, meaning something like long / tall / deep, depending on context. Its form changes with the noun class.

Examples:

• mtu mrefu = a tall person
• mti mrefu = a tall tree
• shimo refu = a deep hole
• mashimo marefu = deep holes
• barabara ndefu = a long road

Since shimo is class 5 singular, the correct adjective form is refu.

That is a very common question.

The adjective -refu refers broadly to a large extent or dimension. In English, we choose different words depending on the noun:

• a tall tree
• a long road
• a deep hole

Swahili often uses the same adjective root, -refu, and the noun tells you how to interpret it.

So with shimo (hole), refu is naturally understood as deep.

Yes, but it means something slightly different in structure.

• shimo refu = a deep hole / the deep hole
  This is a noun phrase.
• Shimo hili ni refu = This hole is deep
  This is a full sentence.

So:

• shimo refu describes a noun
• ni is used when you are making a statement about the noun

Compare:

• Ninaona shimo refu. = I see a deep hole.
• Shimo hili ni refu. = This hole is deep.

The plural is:

Mashimo haya ni marefu.

Breakdown:

• shimo → mashimo = hole → holes
• hili → haya = this → these
• refu → marefu = deep/long/tall → deep/long/tall, agreeing with the plural noun

So all the agreeing words change to match the plural noun class.

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

That means a noun like shimo can mean:

• a hole
• the hole
• just hole

The exact meaning depends on context.

In this sentence, hili already makes the noun specific:

• shimo hili = this hole

So there is no need for a separate word meaning the.

A simple pronunciation guide is:

SHEE-mo HEE-lee nee REH-foo

A few helpful points:

• shi sounds like she
• hili = HEE-lee
• ni = nee
• refu = REH-foo

Swahili words are usually pronounced quite consistently, and the stress normally falls on the second-to-last syllable:

• shiMO
• hiLI
• NI
• reFU

So the sentence has a very regular rhythm.