Learn Hardcore Swahili: Kesho kutwa, polisi watakuwa wametambua chanzo cha moshi barabarani. - The day after tomorrow, the police will have identified the source of the smoke on the road.

Kesho simply means “tomorrow,” i.e. the next calendar day.
Kesho kutwa is an idiomatic way to say “the day after tomorrow.” It literally combines kesho (“tomorrow”) with kutwa (originally “midday” or “the height of the day”) but in modern usage it always means “the day after tomorrow.”

How is the future perfect tense formed in watakuwa wametambua?

Swahili expresses “will have discovered” by combining:

the subject prefix (wa- for “they”)
the future marker -ta-
the auxiliary kuwa (“to be”)
the perfect marker -me-
the verb root (tambua “discover”)

So for polisi (“the police,” 3rd-person plural) you get:
wa + ta + kuwa + me + tambua = watakuwa wametambua (“they will have discovered”).

Why is there no object marker in wametambua before the root?

Object markers (like -ki- for class 7, -li- for class 5, etc.) are used when you’re replacing or emphasizing an object with a pronoun. When the object is a full noun phrase (chanzo cha moshi), the object marker is optional and most speakers simply attach the noun phrase after the verb. Thus wametambua chanzo is perfectly normal.

What role does cha play in chanzo cha moshi?

Cha is the genitive (possessive/linking) concord for noun class 7, which is the class of chanzo (“source”). It links the head noun to its modifier, so chanzo cha moshi literally means “source of smoke.”

Why is it cha moshi and not ya moshi?

Swahili uses different linking words based on the noun class of the head noun: • class 5/6 → ya
• class 7/8 → cha
• class 9/10 → ya (but following special rules)
Because chanzo is class 7, its modifier takes cha, not ya.

What does the suffix -ni in barabarani indicate?

The -ni suffix is the locative case marker in Swahili, roughly equivalent to “at,” “in,” or “on.”
Barabara (“road”) + -ni = barabarani, meaning “on the road.”

Can the position of barabarani change in the sentence?

Yes, Swahili word order is relatively flexible. The usual neutral order is:
Subject – tense/aspect – verb – object – locative.
But you could say for emphasis:
Kesho kutwa polisi watakuwa wametambua barabarani chanzo cha moshi.
Here you’ve shifted the locative right before the object. It still makes sense, though the original order is most common for clarity.

Why use watakuwa wametambua rather than just watatambua or wametambua?

• watatambua = “they will discover” (simple future)
• wametambua = “they have discovered” (present perfect)
To say “they will have discovered” (i.e. the action will be completed by a future point), Swahili uses the future perfect form watakuwa wametambua. It emphasizes completion before that future moment.