Learn Hardcore Swahili: Barabara tuliyopita jana ilikuwa na msongamano mkubwa. - The road we passed yesterday had a big traffic jam.

tuli- = we (subject) + past tense (from sisi tulipita – we passed)
-yo- = relative marker for class 9/10 nouns (here referring to barabara)
pita = verb to pass

So tuliyopita literally means “which we passed” or “that we passed (on)”. It’s a relative verb form: we-past-REL-pass.

Why is it tuliyopita and not tulipopita? What’s the difference?

Both exist, but they mean different things:

tuliyopita – the one which we passed (object-based relative: the road is what was passed)
tulipopita – when/where we passed (time/place-based: referring to the time or place of passing)

In the sentence:

Barabara tuliyopita jana…
The road that we passed yesterday…

We’re describing the road as the thing we passed, so tuliyopita (object relative) is the natural choice.

Where is the word for “that/which”? Why isn’t there an ambayo before tuliyopita?

In many relative clauses, the “that/which” meaning is carried inside the verb, not as a separate word.

English: the road that we passed
Swahili: barabara tuliyopita

The relative marker -yo- in tuliyopita does the job of “that/which”.
You could say barabara ambayo tulipita, but it’s longer and less natural in everyday speech than barabara tuliyopita.

Why is the relative marker -yo- and not something else?

The form of the relative marker depends on the noun class of the noun being described.

barabara (road) is class 9/10.
The relative marker for class 9/10 (for general “which/that”) is -yo-.

So:

barabara tuliyopita – the road that we passed
For a class 1 noun like mtu (person), you’d see -ye- instead:
- mtu tuliyemwona – the person that we saw

Why is it barabara tuliyopita jana and not barabara jana tuliyopita?

Swahili generally keeps time expressions (like jana, yesterday) after the verb phrase they belong to, or at the beginning of the whole sentence.

Here, we have a relative clause:

tuliyopita jana – that we passed yesterday

Putting jana inside that clause after the verb is normal word order.
You could say:

Jana tulipopita kwenye barabara ile, kulikuwa na msongamano mkubwa.
(Yesterday, when we passed on that road, there was a big traffic jam.)

But inside the noun phrase, the order barabara tuliyopita jana is natural and clear.

What is the role of ilikuwa na here?

ilikuwa na = ili- + kuwa + na

ili- = past tense of “to be” for class 9/10 subject (it was)
kuwa = to be
na = with / having

So ilikuwa na msongamano mkubwa literally:
“it was with a big jam” → it had a big traffic jam / there was a heavy traffic jam on it.

In Swahili, kuwa na is a common way to express “to have” or “to be with”.

Why is the verb ilikuwa and not something like alikuwa or walikuwa?

The verb must agree with the subject noun class:

Subject: barabara (road) – class 9/10
Class 9/10 subject prefix in past tense: ili-

So:

barabara ilikuwa – the road was
If the subject were mtu (class 1), you’d say mtu alikuwa – the person was
If the subject were barabara (plural in meaning, multiple roads), you’d still often use the same form because class 9/10 uses i- for both singular and plural in many verbs. Context tells you singular vs plural.

What does msongamano mkubwa mean exactly, and why is mkubwa used?

msongamano = congestion, crowding, traffic jam
- It’s in class 3/4 (like mti/miti – tree/trees).
mkubwa = big, large, major
- It agrees with class 3 singular: m-kubwa

So:

msongamano mkubwa – a big/serious traffic jam
For plural (class 4), you’d say: misongamano mikubwa – big traffic jams

The adjective changes its prefix to match the noun class.

Could I say barabara tulipopita jana kulikuwa na msongamano mkubwa instead?

Yes, and it would be both grammatical and natural, but the focus changes slightly:

Barabara tuliyopita jana ilikuwa na msongamano mkubwa.
→ Focus on the road itself: The road (that we passed yesterday) had a big traffic jam.
Barabara tulipopita jana kulikuwa na msongamano mkubwa.
→ Focus more on what happened when we passed the road: When we passed the road yesterday, there was a big traffic jam.

Both are acceptable; the original sentence treats the road as the main thing being described.

Why is there no preposition like on before “the road”? In English we say “on the road”.

Swahili often does not need a preposition where English does:

barabara tuliyopita – literally: the road that we passed
→ understood as the road that we passed on.

The verb kupita already implies movement past/along something, so adding a preposition is usually unnecessary.
If you really want to be explicit, you can say:

barabara tuliyopitia jana – the road that we went through yesterday
tulipopita kwenye barabara hiyo – when we passed on that road

But in the basic sentence, no extra “on” word is needed.

Why is there no word for “the” like in “the road” or “the big jam”?

Swahili normally does not use separate words for “a” / “the”. The definiteness is understood from:

context
the fact we’re specifying the noun with a relative clause (tuliyopita jana)
the situation being described

So:

barabara tuliyopita jana
can be translated as “the road we passed yesterday” (not “a road”)
msongamano mkubwa
in context will be “a big traffic jam” or “the big traffic jam”, depending on what you mean.

You choose a/the in English; Swahili doesn’t mark this explicitly.

Could I move jana to the front: Jana barabara tuliyopita ilikuwa na msongamano mkubwa?

Yes, that’s grammatical and understandable:

Jana barabara tuliyopita ilikuwa na msongamano mkubwa.

Putting jana first adds extra emphasis on the time (“Yesterday, the road we passed had a big jam”).
Both versions are fine:

Barabara tuliyopita jana… – neutral focus on the road.
Jana barabara tuliyopita… – slightly more focus on yesterday as the time frame.

Is there a shorter, simpler way to say the same thing without the relative form tuliyopita?

Yes, you can express the same idea using two sentences or a different structure:

Jana tulipita kwenye barabara moja. Ilikuwa na msongamano mkubwa.
- Yesterday we passed on a road. It had a big traffic jam.
Jana tulipopita kwenye barabara ile, kulikuwa na msongamano mkubwa.
- Yesterday when we passed on that road, there was a big traffic jam.

The original sentence is just a more compact, noun-focused way to say it:
Barabara tuliyopita jana ilikuwa na msongamano mkubwa.