Ik ben het er niet mee eens, want ik wil eerst vragen kunnen stellen.

This is a very common Dutch pattern.

The fixed expression is het met iemand/iets eens zijn = to agree with someone/something.

In this sentence, it appears in a split form:

• ik ben ... eens = I agree / am in agreement
• het = a placeholder referring to the situation, idea, or statement
• er ... mee = refers back to that / with that
• niet = not

So:

• Ik ben het ermee eens = I agree with it / with that
• Ik ben het er niet mee eens = I do not agree with it / with that

Dutch often breaks up this kind of expression, which can look strange to English speakers at first.

Together, er ... mee works like with it / with that.

This comes from the preposition met (with) combined with a pronoun:

• met dat or met het often becomes ermee
• in a split sentence, it may appear as er ... mee

So in:

• Ik ben het er niet mee eens

the er ... mee part means something like with that.

This is part of a larger Dutch pattern:

• eraan = on it
• erover = about it
• ervoor = for it
• ermee = with it

English learners often find this difficult because English does not bundle prepositions and pronouns in the same way.

In this expression, het is part of the standard pattern het ergens mee eens zijn.

You can think of het as a kind of object placeholder, even when English would not use one. It often refers to an idea, statement, or proposal.

For example:

• Ik ben het met je eens. = I agree with you.
• Ik ben het daar niet mee eens. = I do not agree with that.

So even though English usually just says I agree or I don’t agree, Dutch normally uses het in this construction.

Because niet normally comes before the part of the sentence it negates.

Here, it negates the agreement:

• Ik ben het er mee eens. = I agree with it.
• Ik ben het er niet mee eens. = I do not agree with it.

In Dutch, niet often appears later in the sentence than English not would, especially in sentences with verbs plus fixed expressions or adverbial parts.

So although English says I am not..., Dutch says:

• Ik ben ... niet ...

That is normal Dutch word order.

Yes, ermee is also possible.

You can say:

• Ik ben het er niet mee eens.
• Ik ben het ermee niet eens.

However, Ik ben het er niet mee eens is generally the more natural and common order.

Dutch often allows these combinations either as one word or split apart, but one version may sound more idiomatic in a given sentence. For learners, it is useful to remember the full expression as:

• het er niet mee eens zijn

Both want and omdat can mean because, but they behave differently.

want

• coordinates two main clauses
• the word order after want stays like a normal main clause

So here:

• ..., want ik wil eerst vragen kunnen stellen.

After want, the clause is still main-clause order:

• ik
  • wil

omdat

• introduces a subordinate clause
• the verbs go to the end

That version would be:

• ..., omdat ik eerst vragen wil kunnen stellen.

So want is simpler in word order and often used in spoken Dutch.

Dutch often stacks verbs together at the end of a clause.

Here you have:

• wil = want
• kunnen = can / be able to
• stellen = ask / put
• vragen stellen = ask questions

So:

• ik wil vragen kunnen stellen literally means:
• I want to be able to ask questions

The logic is:

1. stellen goes with vragen
2. kunnen stellen = be able to ask
3. wil ... kunnen stellen = want to be able to ask

English also uses multiple verbs, but Dutch organizes them differently.

Because vragen can mean to ask, but een vraag stellen / vragen stellen is a very common and natural expression meaning to ask a question / ask questions.

Compare:

• Ik wil iets vragen. = I want to ask something.
• Ik wil een vraag stellen. = I want to ask a question.
• Ik wil eerst vragen kunnen stellen. = I want to be able to ask questions first.

So vragen can already be a verb, but vragen stellen is especially common when you mean literally ask questions.

Eerst means first, and here it modifies the whole action vragen kunnen stellen.

So the sentence means:

• I want first to be able to ask questions or more naturally:
• I want to be able to ask questions first

In Dutch, adverbs like eerst, nog, misschien, altijd, and vaak often appear in the middle of the clause, before the verb cluster at the end.

That is why:

• ik wil eerst vragen kunnen stellen

sounds natural.

Not exactly.

The natural expression is:

• Ik ben het daar niet mee eens.

Here daar ... mee means with that, and het still belongs to the fixed pattern.

So:

• Ik ben het er niet mee eens.
• Ik ben het daar niet mee eens.

are both possible, depending on what er or daar refers to.

But:

• Ik ben daar niet mee eens

sounds incomplete to most Dutch speakers, because the expression usually needs het.

Both can refer to something, but they are used slightly differently.

er

Usually refers more weakly or generally to something already understood from context.

• Ik ben het er niet mee eens.

This can feel a bit more abstract: I don’t agree with it/that.

daar

Points more clearly to a specific thing, statement, or situation.

• Ik ben het daar niet mee eens.

This can feel a bit more like I don’t agree with that.

In many contexts, both are possible, but er is very common when the reference is less emphatic.

It is neutral and very natural Dutch. You could use it in everyday conversation, in meetings, in class, or even in reasonably formal contexts.

• Ik ben het er niet mee eens = neutral and standard
• want ik wil eerst vragen kunnen stellen = also neutral and standard

If you wanted to sound more formal or polite, you might soften it a little:

• Ik ben het daar nog niet mee eens, want ik zou eerst vragen willen kunnen stellen.
• Ik ga daar nog niet mee akkoord, want ik wil eerst vragen kunnen stellen.

But the original sentence is perfectly normal and polite enough in many situations.