Die vloer bly skoon sonder dat ons muurverf mors.

Here bly means stay or remain, not be.

So:

• Die vloer is skoon = The floor is clean.
• Die vloer bly skoon = The floor stays/remains clean.

Using bly adds the idea that the floor continues to be clean.

Because bly skoon focuses on the result over time.

• is skoon simply describes the floor’s condition.
• bly skoon suggests that, even during the activity, the floor does not become dirty.

That makes sense in a sentence about painting and not spilling paint.

Sonder dat means without followed by a whole clause.

In this sentence:

• sonder dat ons muurverf mors = without us spilling wall paint

Literally, dat is that, but in English you usually would not translate it word-for-word here. It is just part of the Afrikaans structure.

A useful way to think of it is:

• sonder dat + clause = without + clause / without ...ing

Because Afrikaans often uses sonder dat when a full clause follows, especially when that clause has its own subject.

Here the clause is:

• ons muurverf mors = we spill wall paint

Since that is a complete clause with a subject (ons) and a verb (mors), dat is used.

So Afrikaans says:

• sonder dat ons muurverf mors

where English prefers:

• without spilling wall paint
• without us spilling wall paint

Because sonder dat introduces a subordinate clause, and in Afrikaans subordinate clauses usually send the finite verb to the end.

So:

• Main clause: Die vloer bly skoon
• Subordinate clause: sonder dat ons muurverf mors

Inside that subordinate clause:

• ons = subject
• muurverf = object
• mors = verb, placed at the end

This is very common in Afrikaans after words like dat, omdat, as, terwyl, and similar clause starters.

Here it means we.

That is because it is followed by a noun and then a verb structure that makes it the subject of the clause:

• ons muurverf mors = we spill wall paint

Afrikaans ons can also mean our, for example:

• ons huis = our house

So learners often get confused. In this sentence, though, ons is definitely the subject pronoun we.

Muurverf means wall paint.

It is written as one word because Afrikaans very often forms compound nouns as a single written word.

So:

• muur = wall
• verf = paint
• muurverf = wall paint

This is very normal in Afrikaans. English sometimes writes similar combinations as two words, but Afrikaans usually joins them.

Because muurverf is being used as a general mass noun, like paint in English.

Compare:

• ons mors muurverf = we spill wall paint / paint
• ons mors die muurverf = we spill the wall paint

Without die or 'n, the meaning is more general, not a specific identified container or type of paint.

Mors often means spill, make a mess, or waste, depending on context.

With something like paint, the most natural English idea is:

• spill
• make a mess with

So muurverf mors means something like:

• spill wall paint
• make a mess with wall paint

It is a very useful everyday verb in Afrikaans.

Because skoon is used predicatively here, after the linking verb bly.

In Afrikaans, adjectives used after verbs like is, bly, lyk, and word usually do not take the attributive ending.

So:

• Die vloer is skoon = The floor is clean.
• Die vloer bly skoon = The floor stays clean.

But before a noun, adjective forms can change:

• 'n skoon vloer = a clean floor

So skoon stays plain here because it is describing the floor after bly, not directly before the noun.

Not in exactly the same structure.

Sonder om ... te is often used for without doing something, but it works best when the subject is the same or understood.

For example:

• Ons verf sonder om muurverf te mors.
  = We paint without spilling wall paint.

In your sentence, the main subject is die vloer, but the one doing the spilling is ons. Because the subordinate idea has its own explicit subject, sonder dat ons ... mors is the natural choice.

So:

• Die vloer bly skoon sonder dat ons muurverf mors. = natural
• Die vloer bly skoon sonder om muurverf te mors. = less natural, because it leaves the spiller unclear or awkwardly implied