Ik wil mijn kamer opruimen zoals mijn zus dat doet.

Because opruimen is a separable verb.

Its full dictionary form is opruimen, meaning to tidy up / clean up. In some sentence patterns, it stays together as opruimen. In others, it splits into:

• ruim = the conjugated verb
• op = the separable prefix

In your sentence, it stays together because it comes after wil:

• Ik wil mijn kamer opruimen.

But in a main clause without another verb, it usually splits:

• Ik ruim mijn kamer op.

That is a very common feature of Dutch separable verbs.

After a modal verb like willen , Dutch uses the infinitive of the main verb.

So:

• Ik wil = I want
• opruimen = to tidy up

Together:

• Ik wil mijn kamer opruimen.

This is similar to English I want to tidy my room, except Dutch does not use a separate word for to before the infinitive in this structure.

Dutch often puts the conjugated verb early in the clause and the other verb later.

Here:

• Ik = subject
• wil = conjugated verb
• mijn kamer = object
• opruimen = infinitive at the end

So the basic structure is:

• subject + finite verb + object + infinitive

This is very normal in Dutch with modal verbs such as:

• kunnen
• moeten
• mogen
• willen
• zullen

For example:

• Ik kan Nederlands spreken.
• Zij moet morgen werken.

Zoals means like, the way, or as, depending on the sentence.

Here it introduces a comparison:

• zoals mijn zus dat doet = like the way my sister does that / as my sister does

So the speaker wants to tidy their room in the same way their sister does.

A useful way to think of it is:

• zoals = in the same way that

Here, dat stands for the action already mentioned: opruimen.

So:

• Ik wil mijn kamer opruimen zoals mijn zus dat doet.

literally works like:

• I want to tidy my room like my sister does that.

That sounds a little strange in English, but in Dutch it is natural. The dat points back to the earlier idea of tidying up.

You can think of dat here as meaning:

• that
• so
• it

But the most important point is that it refers back to the action, not to a specific noun.

Sometimes Dutch speakers do omit it in casual speech, but zoals mijn zus dat doet is the clearest and most standard version here.

Including dat makes it explicit that your sister does the same thing, meaning tidies up in that way.

So for a learner, it is safest to use:

• zoals mijn zus dat doet

rather than:

• zoals mijn zus doet

because without dat, the sentence may feel less complete.

Because zoals mijn zus dat doet is a subordinate clause, and in Dutch subordinate clauses the conjugated verb often goes to the end.

Compare:

Main clause:

• Mijn zus doet dat.

Subordinate clause:

• zoals mijn zus dat doet

This verb-final pattern is one of the most important features of Dutch word order.

Other examples:

• omdat ik moe ben
• dat zij morgen komt
• wanneer hij tijd heeft

So doet is at the end because the clause is introduced by zoals.

In modern standard Dutch, the normal possessive form before a noun is:

• mijn = my

So:

• mijn kamer
• mijn zus

The form mijne is old-fashioned, dialectal, or used in very specific styles, but not standard in ordinary modern Dutch.

So learners should normally use:

• mijn broer
• mijn vriendin
• mijn huis

Usually kamer means room, but in many everyday contexts mijn kamer often refers to my bedroom or my own room, especially when talking about tidying it.

So depending on context, it could mean:

• my room
• my bedroom

Dutch kamer is a little broader than English bedroom, so context matters.

No. English like can correspond to different Dutch words.

In comparisons of manner, zoals is often right:

• Doe het zoals ik het doe.
• Do it the way I do it.

But in other cases Dutch may use other words, for example:

• als in some comparisons
• graag for to like doing something
• houden van for to like/love someone or something

So you should not assume English like always becomes zoals. In this sentence, though, zoals is the correct choice because it means in the same way as.

Yes, but it means something slightly more explicit.

Your original sentence:

• Ik wil mijn kamer opruimen zoals mijn zus dat doet.

This means:

• I want to tidy my room the way my sister does.

A more expanded version could be:

• Ik wil mijn kamer opruimen zoals mijn zus haar kamer opruimt.

That literally says:

• I want to tidy my room the way my sister tidies her room.

This version repeats the full action instead of using dat. Both are possible, but the original sentence sounds more natural because it avoids unnecessary repetition.

There are three big patterns here:

1. Modal verb + infinitive

   • Ik wil ... opruimen
   • Zij kan ... lezen
   • Wij moeten ... vertrekken

2. Separable verb behavior

   • infinitive: opruimen
   • finite form in a main clause: ruimt ... op

3. Subordinate clause word order

   • zoals mijn zus dat doet
   • verb goes to the end

So this sentence is a very good model for building others, such as:

• Ik wil koken zoals mijn vader dat doet.
• Ik wil Nederlands leren zoals mijn vriend dat doet.
• Ik wil mijn bureau organiseren zoals mijn collega dat doet.