Met de bijdrage betalen wij de aanbetaling.

Because Dutch main clauses usually follow the V2 rule: the finite verb comes in the second position.

Here, the sentence starts with Met de bijdrage. That whole prepositional phrase takes the first position, so the verb must come next:

• Met de bijdrage
  • betalen
    • wij
      • de aanbetaling

If you started the sentence with the subject, then you would get:

• Wij betalen de aanbetaling met de bijdrage.

Both are correct. The version with Met de bijdrage puts more emphasis on how the payment is made.

Yes. That is a completely normal sentence.

The difference is mostly emphasis:

• Met de bijdrage betalen wij de aanbetaling.
  Focuses first on the means: with the contribution
• Wij betalen de aanbetaling met de bijdrage.
  Starts more neutrally with the subject: we

English often does this too:

• With the contribution, we pay the down payment.
• We pay the down payment with the contribution.

So this is mostly a word-order and emphasis choice, not a change in basic meaning.

Here met means with, in the sense of using something as the means to do something.

So:

• Met de bijdrage = with the contribution / using the contribution

It tells you what resource is being used to pay.

In Dutch, met is very common for this idea:

• Ik schrijf met een pen. = I write with a pen.
• Wij betalen met contant geld. = We pay with cash.

So in your sentence, met introduces the thing that makes the payment possible.

They are two different kinds of money-related nouns.

• bijdrage = contribution, payment toward something, sometimes a fee or amount given to help cover costs
• aanbetaling = down payment, deposit paid in advance, usually part of a larger total price

So the sentence is saying that one sum of money, the contribution, is being used to pay another specific sum, the down payment.

A learner should not confuse them:

• bijdrage is the money that comes in or is provided
• aanbetaling is the upfront payment that must be paid

Because both bijdrage and aanbetaling are common-gender singular nouns in Dutch, and the definite article for those nouns is de.

So:

• de bijdrage
• de aanbetaling

This is something you usually just have to learn with the noun.

Also, de here is the definite article, meaning the speaker is talking about a specific contribution and a specific down payment, not just any one.

Compare:

• de bijdrage = the contribution
• een bijdrage = a contribution

Because Dutch normally writes compound nouns as one word.

So aanbetaling is a compound noun, not two separate words.

This is very common in Dutch:

• huisdeur = house door / front door
• zorgverzekering = health insurance
• aanbetaling = down payment

English often writes similar ideas as two words, but Dutch prefers one combined noun. So aan betaling would be wrong here.

Both are correct, but we is much more common in everyday spoken Dutch.

So in normal conversation, many speakers would say:

• Met de bijdrage betalen we de aanbetaling.

Wij is still perfectly correct, but it can sound a bit more formal, careful, or emphatic depending on context.

A useful rule of thumb:

• we = common in speech and informal writing
• wij = more formal, or used for emphasis

In Dutch, singular countable nouns usually need an article or some other determiner, just as in English.

So you normally say:

• de aanbetaling = the down payment
• een aanbetaling = a down payment
• onze aanbetaling = our down payment

Using just aanbetaling by itself would usually sound incomplete in a sentence like this.

The article de shows that the speaker means a particular down payment already known from the context.

Use de when you mean a specific one that is known or identifiable. Use een when it is non-specific or mentioned for the first time.

So:

• Met de bijdrage betalen wij de aanbetaling.
  = both amounts are specific and known in the situation

But you could say:

• Met een bijdrage kunnen wij een aanbetaling doen.
  = with some contribution, we can make a down payment

That sounds less specific and more general.

So the choice between de and een works much like the and a/an in English.

A simple learner-friendly pronunciation guide would be:

• bijdrage ≈ BYE-draa-ghuh
• aanbetaling ≈ AHN-buh-TAA-ling

A few helpful points:

• In bijdrage, the first part bij sounds a bit like English bye
• The g in standard Dutch is a throat sound, not an English g
• In aanbetaling, the stress is on taa: aan-be-TAA-ling
• The final -e in bijdrage is a weak uh sound

Pronunciation varies somewhat by region, especially the g, but those approximations are good for a learner.