Learn Hardcore Dutch: Ik weet niet of de bibliotheek die roman deze week al kan uitlenen. - I don’t know whether the library can already lend out that novel this week.

Ik weet niet of … = I don’t know if / whether …
Dutch of has two main uses:
- as “or”:
  - Wil je koffie of thee? = Do you want coffee or tea?
- as “if / whether” introducing an indirect yes/no question:
  - Ik weet niet of hij komt. = I don’t know if he is coming.

You cannot use als or wanneer here, because those normally introduce conditions (if X happens, then Y) or times (when X happens), not indirect questions.

So of in this sentence = if / whether, not English of.

Why does the verb go to the end in … of de bibliotheek die roman deze week al kan uitlenen?

Because of introduces a subordinate clause in Dutch. In subordinate clauses:

The conjugated verb (here kan) usually moves to the end of the clause.
Any other verbs (here uitlenen) also go at the end, forming a verb cluster.

Structure of the clause:

de bibliotheek – subject
die roman – direct object
deze week – time expression
al – adverb
kan uitlenen – verb cluster at the end

So:

Main clause: De bibliotheek kan die roman deze week al uitlenen.
Subordinate clause: … of de bibliotheek die roman deze week al kan uitlenen.

Putting kan earlier (e.g. … of de bibliotheek kan die roman … uitlenen) would sound wrong in Dutch.

Why is it kan uitlenen and not something like uit kan lenen?

Uitlenen is a separable verb:

uit (particle) + lenen (verb) → uitlenen (to lend out).

Rules:

With one finite verb in a main clause, it splits:
- De bibliotheek leent die roman uit.
  (The library lends out that novel.)
With a modal or auxiliary verb, the separable verb usually stays together as an infinitive:
- De bibliotheek kan die roman uitlenen.
- De bibliotheek wil die roman uitlenen.
In subordinate clauses, the entire verb group goes to the end:
- … of de bibliotheek die roman kan uitlenen.

So kan uitlenen at the end is correct; uit kan lenen is wrong in standard Dutch.

Why is it uitlenen and not just lenen?

Dutch distinguishes clearly between:

lenen – to borrow (take something temporarily)
- Ik leen een boek van de bibliotheek.
  I borrow a book from the library.
uitlenen – to lend out (give something temporarily)
- De bibliotheek leent boeken uit.
  The library lends out books.

Since the library is the one giving the book, Dutch needs uitlenen, not lenen.

Why is it die roman and not dat roman or just de roman?

Two points: gender and demonstratives.

Gender / article
- roman takes the article de: de roman (a de-word).
- For de-words, the far demonstrative is die, the near one is deze:
  - die roman – that novel
  - deze roman – this novel
- dat is used with het-words:
  - dat boek – that book (because het boek)
Why use a demonstrative at all?
die roman suggests:
- a specific novel both speaker and listener know (mentioned earlier, or visible), or
- some emotional/attitudinal distance (that novel rather than just the novel).

If you just want to say the novel neutrally, you could say:

… of de bibliotheek de roman deze week al kan uitlenen.

But in the given sentence the speaker is clearly referring to a specific, identifiable novel: die roman (that novel).

What exactly does al mean here, and why is it before kan?

In this sentence al means already:

deze week al ≈ already this week / as early as this week

Function and position:

al is an adverb that modifies the time frame:
- de bibliotheek die roman deze week al kan uitlenen
  → whether the library can lend out that novel already this week
Typical neutral order inside the middle field is:
- subject → object(s) → time → small adverbs → verb cluster

So:

de bibliotheek (subject)
die roman (object)
deze week (time)
al (adverb)
kan uitlenen (verbs)

You could also say … die roman al deze week kan uitlenen, which slightly shifts the emphasis to “already this week (and not later)”, but the original order is very natural and neutral.

Why is the negation niet placed after weet and before of?

Here niet is negating the knowing, not the lending.

Ik weet niet of … = I don’t know whether …
If you moved niet into the subordinate clause, you would change the meaning.

Compare:

Ik weet niet of de bibliotheek die roman deze week al kan uitlenen.
→ I don’t know whether the library can lend out that novel this week already. (neutral)
Ik weet of de bibliotheek die roman deze week al niet kan uitlenen.
→ I know that the library cannot lend out that novel this week already.
(Here you do know something; you know they cannot do it.)

So in pattern Ik weet (het) niet + of-clause, niet belongs directly to weet, and it must come before of.

Why is it kan and not mag? Both can translate as “can”, right?

Yes, both can translate as “can”, but they express different ideas:

kan = is able to / is possible to (ability, possibility, practical constraints)
mag = is allowed to / may (permission, rules)

In this context, kan uitlenen typically means:

the library is able to lend it out (it’s available, not reserved, not reference-only, etc.)

If you said … al mag uitlenen, you’d focus on permission:

whether some rule allows the library to lend it out at all.

So kan uitlenen is the natural choice when you are wondering about practical possibility, not legal/official permission.

Can the order of die roman and deze week be changed?

Yes, but the nuance changes slightly.

Standard neutral order (object before time):

… of de bibliotheek die roman deze week al kan uitlenen.

Alternatives:

… of de bibliotheek deze week die roman al kan uitlenen.
- Puts a bit more emphasis on deze week (this week specifically).
… of de bibliotheek die roman al deze week kan uitlenen.
- Stresses al deze week (= already / as early as this week).

All are grammatical; the given sentence is the most neutral-sounding version.

If I start the sentence with the of-clause, does the word order change?

Yes, but inside the of-clause the word order stays the same; what changes is the main clause afterwards.

Original:

Ik weet niet of de bibliotheek die roman deze week al kan uitlenen.

Fronted subordinate clause:

Of de bibliotheek die roman deze week al kan uitlenen, weet ik niet.

Notice:

In the of-clause, the verbs still come at the end: … al kan uitlenen.
In the main clause that follows, verb–subject inversion occurs: weet ik niet instead of ik weet niet.

So the internal order of … of de bibliotheek die roman deze week al kan uitlenen does not change; only the order in the main clause does.