Op watter bladsy van die tydskrif is die artikel oor die nuwe museum?

Because Afrikaans usually uses the preposition that belongs with the noun.

Here, op ... bladsy means on ... page, so when you ask the question, you keep op:

• op watter bladsy = on which page

This is very similar to English, where you would naturally say On which page... ? or more casually Which page... on?

So Op watter bladsy is the normal and correct way to ask this.

Watter means which.

It is used to ask someone to choose or identify one thing from a set:

• Watter boek? = Which book?
• Watter bladsy? = Which page?

In this sentence:

• Op watter bladsy ... ? = On which page ... ?

So watter works very much like English which.

This is because Afrikaans uses verb-second word order in main clauses.

The finite verb usually comes second in the sentence. Since the sentence begins with the question phrase Op watter bladsy van die tydskrif, the verb is must come next:

• Op watter bladsy van die tydskrif is die artikel ... ?

If you put the subject first, then you would get:

• Die artikel is op bladsy 5. = The article is on page 5.

So in the question, the fronted phrase takes first position, and is moves to second position.

Van die tydskrif means of the magazine or from the magazine, depending on context.

In this sentence, it means:

• bladsy van die tydskrif = page of the magazine / page in the magazine

Word by word:

• van = of / from
• die tydskrif = the magazine

So the whole phrase Op watter bladsy van die tydskrif means On which page of the magazine.

In Afrikaans, die is the definite article for the, and it does not change for gender or number.

So all of these use die:

• die tydskrif = the magazine
• die artikel = the article
• die nuwe museum = the new museum

Unlike some other languages, Afrikaans does not have different forms like masculine/feminine/neuter the. It is simply die in all these cases.

Oor here means about.

So:

• die artikel oor die nuwe museum = the article about the new museum

This is a very common use of oor:

• ’n boek oor geskiedenis = a book about history
• ons praat oor die weer = we are talking about the weather

Be aware that oor can also have other meanings in different contexts, such as over, but here it clearly means about.

Because Afrikaans adjectives often take an -e ending when they come before a noun.

So:

• nuut = new (basic form)
• die nuwe museum = the new museum

This -e ending is very common in attributive adjectives, meaning adjectives placed before nouns.

Compare:

• Die museum is nuut. = The museum is new.
• die nuwe museum = the new museum

So nuut is used after the verb, but nuwe is used before the noun here.

Yes, tydskrif is the normal Afrikaans word for magazine.

It is made up of:

• tyd = time
• skrif = writing

But you should learn tydskrif as a whole vocabulary item meaning magazine / journal.

Example:

• Ek lees ’n tydskrif. = I am reading a magazine.

No. In natural English, you say on which page, not in which page.

Afrikaans also uses op here, which matches English on:

• Op watter bladsy ... ? = On which page ... ?

So on which page is the best translation.

You would usually answer with the page number.

For example:

• Die artikel is op bladsy 12. = The article is on page 12.
• Dit is op bladsy 12. = It is on page 12.

Notice the normal statement word order:

• Die artikel is ... not
• Is die artikel ...

No, not in standard Afrikaans.

• watter = which
• wat = usually what or that

Since the question is asking which page, you need watter:

• Op watter bladsy ... ?

Using wat here would be ungrammatical.

The structure is:

• Op watter bladsy van die tydskrif = question phrase
• is = verb
• die artikel oor die nuwe museum = subject noun phrase

So the pattern is:

Question phrase + verb + subject

That is a very common pattern in Afrikaans wh-questions, especially when something other than the subject comes first.