Nyani wawili wamekaa juu ya mti.

A quick breakdown:

• Nyani = monkey / monkeys
• wawili = two
• wamekaa = they are sitting / they have sat down and are now seated
• juu ya = on top of / above / up on
• mti = tree

So the sentence structure is basically:

• Nyani wawili = two monkeys
• wamekaa = are sitting
• juu ya mti = on a tree / up in the tree

Because some Swahili nouns have the same form in singular and plural. Nyani is one of them.

So:

• nyani can mean monkey
• nyani can also mean monkeys

You tell the number from the other words around it, especially:

• wawili = two
• wa- in wamekaa = they

Those agreement clues show clearly that this sentence is about more than one monkey.

Because Swahili numbers from one to five often agree with the noun class.

For animate beings such as people, and very often animals in agreement, you use forms like:

• mmoja = one
• wawili = two
• watatu = three
• wanne = four
• watano = five

So wawili is the correct form here because the sentence treats nyani as an animate plural.

A learner coming from English often expects just one general word for two, but Swahili usually makes it match the noun class.

Wamekaa can be broken down like this:

• wa- = they
• -me- = perfect marker
• -kaa = sit / stay / remain

So literally it is something like they have sat. But in natural English, with a verb like kukaa, it often means:

• they are sitting
• they are seated
• they have sat down

In other words, it often describes a present state resulting from an action.

In Swahili, verbs usually include a subject marker. Here:

• wa- = they

That subject marker agrees with the subject, which is two monkeys.

So unlike English, where they is a separate word, Swahili often builds that information directly into the verb.

That is why wamekaa already contains the idea of they are sitting.

Juu ya is a very common Swahili expression meaning:

• on top of
• above
• up on

Literally, it comes from a noun-like idea of upper part / top, plus a linker:

• juu = top / upper part
• ya = of

So juu ya mti is literally something like the top of a tree or above the tree, but in normal use it works like a prepositional phrase: on the tree or up in the tree.

Because Swahili does not have articles like English a, an, and the.

So mti can mean:

• a tree
• the tree

The context tells you which one is meant.

That is very normal in Swahili. English speakers often want every noun to show definiteness, but Swahili usually leaves that unstated unless something in the context makes it clear.

Mostly, yes.

This sentence follows a pattern very similar to English:

• subject: Nyani wawili
• verb: wamekaa
• location: juu ya mti

So it is basically:

• Two monkeys
  • are sitting
    • on a tree

One important difference is inside the subject phrase:

• Swahili puts the number after the noun
• nyani wawili = monkeys two

That is normal in Swahili noun phrases.

Yes. The verb kukaa has a wider range than just sit.

Depending on context, it can mean:

• sit
• stay
• remain
• live
• reside

But in Nyani wawili wamekaa juu ya mti, the location phrase juu ya mti strongly suggests the physical meaning are sitting or are perched.

So context is what tells you which English translation fits best.

Literally, juu ya mti is closer to on top of / above the tree. But in real usage, it can also be understood more naturally as up in the tree or on the tree, depending on context.

English and Swahili do not always divide space in exactly the same way. So a very literal translation is not always the most natural one.

If the meaning shown to the learner is something like Two monkeys are sitting in a tree, that is still a reasonable way to understand the sentence.

A rough guide:

• Nyani ≈ nya-ni
• wawili ≈ wa-wi-li
• wamekaa ≈ wa-me-ka-a
• juu ya ≈ joo ya
• mti ≈ mti

A few useful pronunciation notes:

• ny sounds like the ny in canyon
• w is like English w
• j is like English j in jam
• Swahili vowels are usually clear and consistent:
  • a as in father
  • e as in bed but often a bit cleaner
  • i as in machine
  • o as in told without much glide
  • u as in rule
• Stress is usually on the second-to-last syllable

So you would naturally stress:

• nyaNI
• waWIli
• wameKAA
• JUU ya MTI