Usumbufu ulikuwa mkubwa kiasi kwamba hatukulala usiku.

Usumbufu can mean disturbance, trouble, inconvenience, or nuisance, depending on context. In this sentence, it most naturally means something like the disturbance or the noise/trouble that kept people awake.

So here it is not just a small inconvenience; it is something serious enough to affect sleep.

Swahili verbs must agree with the noun they refer to. The noun usumbufu takes the subject agreement u-, so the verb begins with u-:

• u- = subject agreement for this noun
• -li- = past tense
• -kuwa = be

So ulikuwa means it was.

A native English speaker may expect one general word for it was, but in Swahili the form changes depending on the noun class of the subject.

Adjectives in Swahili also agree with the noun they describe. Since usumbufu takes this agreement pattern, -kubwa becomes mkubwa.

So:

• kubwa = big, great
• mkubwa = big/great, agreeing with usumbufu

In this sentence, mkubwa is better understood as great, serious, or severe, not physically big.

Kiasi kwamba means so...that, to such an extent that, or to the point that.

It introduces a result:

• Usumbufu ulikuwa mkubwa = The disturbance was great
• kiasi kwamba hatukulala usiku = so great that we did not sleep at night

This is a very useful pattern in Swahili for expressing cause and result.

Not with the same meaning.

• sana means very
• kiasi kwamba means so...that / to such an extent that

Compare:

• Usumbufu ulikuwa mkubwa sana. = The disturbance was very great.
• Usumbufu ulikuwa mkubwa kiasi kwamba hatukulala usiku. = The disturbance was so great that we did not sleep at night.

The second sentence includes the consequence; the first one does not.

Hatukulala breaks down like this:

• ha- = negative
• -tu- = we
• -ku- = past tense
• -lala = sleep

So hatukulala means we did not sleep.

This is a useful form to learn because Swahili negative verbs often look quite different from affirmative ones.

For comparison:

• tulilala = we slept
• hatukulala = we did not sleep

In Swahili, many time expressions do not need a preposition. So usiku by itself can mean:

• at night
• during the night
• sometimes that night, depending on context

English often needs words like at, during, or on, but Swahili frequently leaves them out.

It depends on context.

In isolation, usiku most directly means at night or during the night. But in a sentence like this, English speakers often translate it more naturally as that night or even all night, especially if a specific incident is being described.

Possible natural translations are:

• The disturbance was so great that we didn’t sleep at night.
• The disturbance was so great that we didn’t sleep that night.
• The disturbance was so great that we didn’t sleep all night.

The exact best choice depends on the wider context.

A fairly literal translation is:

The disturbance was great to such an extent that we did not sleep at night.

A more natural English translation would be:

The disturbance was so great that we didn’t sleep that night.

Literal breakdown:

• Usumbufu = disturbance
• ulikuwa = was
• mkubwa = great / severe
• kiasi kwamba = so...that / to such an extent that
• hatukulala = we did not sleep
• usiku = at night / during the night

Yes. Swahili often uses -kubwa in places where English might prefer great, serious, or severe.

So mkubwa does not only mean physically big. With abstract nouns like usumbufu, it can describe degree or intensity.

That is why usumbufu mkubwa can mean:

• great disturbance
• serious disturbance
• severe inconvenience

The given word order is natural and standard:

Usumbufu ulikuwa mkubwa kiasi kwamba hatukulala usiku.

Swahili does allow some flexibility, but this is the clearest default order:

1. subject: Usumbufu
2. verb: ulikuwa
3. complement: mkubwa
4. result clause: kiasi kwamba hatukulala usiku

So for a learner, this is a very good model sentence to follow.