Huduma ya usafi wa vyumba ilikuwa nzuri kiasi kwamba tuliamua kukaa.

Literally, it is something like service of cleanliness of rooms.

A more natural English rendering is room-cleaning service or housekeeping service.

The phrase breaks down like this:

• huduma = service
• ya = of
• usafi = cleanliness / cleaning
• wa = of
• vyumba = rooms

So the whole noun phrase is built in layers:

• usafi wa vyumba = cleanliness/cleaning of rooms
• huduma ya usafi wa vyumba = service of room cleaning / housekeeping service

In Swahili, the word that works like of changes to match the noun class of the noun before it.

So:

• huduma ya usafi: ya agrees with huduma
• usafi wa vyumba: wa agrees with usafi

This is very important: the linker agrees with the noun that comes before it, not the noun that comes after it.

So even though vyumba is class 8 and often goes with vya, you do not say usafi vya vyumba, because the linker is agreeing with usafi, not with vyumba.

Usafi is a noun, meaning cleanliness or cleaning in the sense of a thing or concept.

Kusafisha is a verb in infinitive form, meaning to clean.

In this sentence, the speaker is naming a type of service, so a noun works very naturally:

• huduma ya usafi wa vyumba = housekeeping / room-cleaning service

You could also hear huduma ya kusafisha vyumba, which would mean something like room-cleaning service too, but it focuses more directly on the action to clean rooms.
Using usafi sounds a bit more like cleanliness/housekeeping as a service.

Vyumba is the plural of chumba, which means room.

So:

• chumba = room
• vyumba = rooms

This is a class 7/8 noun pair in Swahili:

• singular: ki-/ch- type
• plural: vi-/vy- type

So chumba becomes vyumba.

Because huduma is the subject of the sentence, and the verb has to agree with it.

Ilikuwa can be broken down like this:

• i- = subject marker for the noun class of huduma
• -li- = past tense
• -kuwa = be

So ilikuwa means it was.

Since huduma belongs to a noun class that uses i- in this kind of agreement, the sentence says:

• Huduma ... ilikuwa nzuri = The service ... was good

Adjectives in Swahili often agree with the noun class of the noun they describe.

The adjective root here is -zuri, meaning good / nice.

Because it describes huduma, it takes the form nzuri.

So:

• huduma ... nzuri = good service

Different noun classes give different adjective forms. For example:

• mtu mzuri = a good person
• jambo zuri = a good thing
• huduma nzuri = good service

So nzuri is correct because it matches huduma.

Kiasi kwamba means so ... that or to such an extent that.

In this sentence:

• ilikuwa nzuri kiasi kwamba tuliamua kukaa

the idea is:

• it was so good that we decided to stay

It links the first idea to the result.

A useful way to remember it is:

• kiasi = amount / measure / extent
• kwamba = that

So together, it gives the idea of to such an extent that.

Tuliamua kukaa means we decided to stay.

It breaks down like this:

• tu- = we
• -li- = past tense
• -amua = decide

So tuliamua = we decided.

Then kukaa is the infinitive form of kaa, so literally to stay / to remain / to sit, depending on context.

Here it means to stay.

So:

• tuliamua kukaa = we decided to stay

This is a very common pattern in Swahili:

• aliamua kwenda = he/she decided to go
• tuliamua kukaa = we decided to stay

No. Kukaa has several related meanings, depending on context.

It can mean:

• to sit
• to stay
• to remain
• to live somewhere

Examples:

• kaa chini = sit down
• tutakaa hapa = we will stay here
• anakaa Dar es Salaam = he/she lives in Dar es Salaam

In your sentence, because the context is about a hotel or lodging-type situation, kukaa is best understood as to stay.

Swahili normally does not use articles like English the and a/an.

So a noun like huduma can mean:

• service
• the service
• a service

The exact meaning depends on context.

That is why Huduma ya usafi wa vyumba ilikuwa nzuri can naturally be translated as:

• The housekeeping service was good or
• Housekeeping service was good

In normal English, we usually add the because it sounds more natural in that context.

Yes, it is understandable and natural.

It is a descriptive phrase meaning the service connected with cleaning rooms. In hotel context, that is basically housekeeping.

Depending on context, Swahili speakers might also use other expressions, but huduma ya usafi wa vyumba is clear and correct.

A learner should notice that Swahili often expresses ideas like this with noun chains, where English might prefer one compact word such as housekeeping.

Yes, that is possible, but so good that is usually the best match here.

Kiasi kwamba most directly gives the idea of:

• so ... that
• to such an extent that

So the strongest natural translation is:

• The housekeeping service was so good that we decided to stay.

If you say good enough that, the meaning becomes slightly different in English. Good enough often suggests sufficient, while nzuri kiasi kwamba more strongly emphasizes the degree of goodness and the result it caused.