Watu waliishi katika enzi ya kale.

Watu means people. Its singular form is mtu, meaning person.

This is a very common noun pair in Swahili:

• mtu = person
• watu = people

It belongs to the noun class used for human beings, and that is why the verb in the sentence also uses a matching human-plural prefix.

Waliishi can be broken down like this:

• wa- = they, matching watu
• -li- = past tense marker
• -ishi = verb root meaning live

So:

• waliishi = they lived

The dictionary form of the verb is kuishi, meaning to live.

The wa- is the subject prefix, and it agrees with watu.

In Swahili, verbs usually show who is doing the action inside the verb itself. Since watu is plural and refers to people, the verb uses wa-.

Compare:

• mtu aliishi = the person lived
• watu waliishi = the people lived

So the verb changes to match the subject.

Swahili handles these ideas differently from English.

• English often uses did to show past tense.
• Swahili usually puts the tense marker inside the verb itself.

So in waliishi, the -li- already tells you the action is in the past.

Also, Swahili does not have articles like a, an, or the. Whether something is people or the people, an age or the age, is usually understood from context.

That means:

• watu can mean people or the people
• enzi ya kale can mean ancient times or the ancient age, depending on context

Katika means in, within, or sometimes during, depending on context.

In this sentence, it is most natural to understand it as:

• in
• or during

So katika enzi ya kale means something like:

• in ancient times
• during the ancient age

Katika is a very common and slightly formal-looking preposition. It often appears in writing and careful speech.

Enzi ya kale is a time expression.

Its parts are:

• enzi = age, era, period, time
• ya = linking word, roughly of
• kale = ancient, old, long ago

So the whole phrase means:

• the ancient age
• ancient times
• olden days

In natural English, you would usually translate the whole phrase, not each word separately.

Ya is an agreement word that links enzi with what follows it.

A simple way to think of it is that Swahili often uses a connector like of, but that connector changes form depending on the noun class of the noun before it.

So here:

• enzi ya kale = age/era of old times or more naturally ancient age / ancient times

You may also come across enzi za kale in other contexts. The version in your sentence, enzi ya kale, treats it as a single age or era.

The sentence has a very normal Swahili order:

• Watu = subject
• waliishi = verb
• katika enzi ya kale = time phrase

So:

• Watu waliishi katika enzi ya kale. = a neutral statement

But Swahili can move the time phrase to the front for emphasis or style:

• Katika enzi ya kale, watu waliishi...

That would still be grammatical and natural. It just foregrounds the time expression.

In a sentence like this, waliishi usually expresses a general past fact or situation.

So the meaning is close to:

• People lived in ancient times

It does not necessarily focus on one single event. It simply places the state of living in the past.

The past marker -li- is fairly broad, and context tells you whether the meaning is:

• a simple past fact
• a longer past situation
• a historical description

Here it sounds like a historical statement.

A rough pronunciation guide is:

• Watu = WAH-too
• waliishi = wah-lee-EE-shee
• katika = kah-TEE-kah
• enzi = EN-zee
• ya = yah
• kale = KAH-leh

A few helpful points:

• Swahili vowels are usually pronounced clearly.
• In waliishi, both i vowels are sounded.
• sh sounds like the sh in shoe.
• Swahili stress usually falls on the second-to-last syllable.

So the full sentence is approximately:

WAH-too wah-lee-EE-shee kah-TEE-kah EN-zee yah KAH-leh