Mijn zus wordt vroeg wakker als de vogels zingen.

Dutch often expresses to wake up as wakker worden, literally to become awake.

• wordt = becomes
• wakker = awake

So Mijn zus wordt wakker is the normal way to say My sister wakes up.

English uses a single verb, wake up, but Dutch very often uses this two-part expression instead. That is completely natural Dutch.

You may also hear wakker worden in the infinitive:

• Ik wil vroeg wakker worden. = I want to wake up early.

Because wakker worden behaves like a fixed verbal expression, but in a main clause Dutch usually puts the finite verb in the second position.

The full infinitive is:

• wakker worden

But in a main clause, the conjugated part moves forward:

• Mijn zus wordt vroeg wakker.

So:

• wordt = the finite, conjugated verb
• wakker stays later in the clause

This is very common in Dutch with verbal combinations.

Compare:

• Ik sta vroeg op.
• Hij komt morgen terug.
• Mijn zus wordt vroeg wakker.

wordt is the third person singular present tense of worden.

The subject is mijn zus, which is singular, so Dutch uses wordt.

A quick overview of worden in the present tense:

• ik word
• jij wordt / word
• hij/zij/het wordt
• wij worden
• jullie worden
• zij worden

So mijn zus wordt matches the subject correctly.

Because als de vogels zingen is a subordinate clause.

In Dutch subordinate clauses, the conjugated verb usually goes to the end. The word als introduces that clause.

So:

• main clause: Mijn zus wordt vroeg wakker
• subordinate clause: als de vogels zingen

Inside the subordinate clause:

• de vogels = subject
• zingen = verb, placed at the end

This is one of the most important Dutch word-order patterns to learn.

Compare:

• Ik blijf thuis als het regent.
• Wij eten wanneer hij komt.
• Ze lacht omdat hij iets grappigs zegt.

Here als means when.

In Dutch, als can sometimes mean if, but in this sentence it clearly means when, because it describes something that happens regularly or naturally:

• Mijn zus wordt vroeg wakker als de vogels zingen.

That suggests a repeated situation: whenever the birds sing, she wakes up early.

For learners, this is a useful rule of thumb:

• als can mean when in general or repeated situations
• als can also mean if
• wanneer can also mean when, often sounding a bit more explicit or formal

So in this sentence, als is perfectly normal.

Yes, in many contexts you could.

• Mijn zus wordt vroeg wakker wanneer de vogels zingen.

This is grammatical, but als often sounds more natural for a repeated, general situation like this.

A simple learner-friendly distinction is:

• als = very common for when in repeated situations
• wanneer = also when, sometimes a bit more formal, emphatic, or question-like

In everyday Dutch, als is extremely common here.

Dutch usually uses the definite article when talking about a specific group in a general scene like this.

• de vogels = the birds

Even though English might sometimes say just birds in a broad statement, Dutch often prefers de vogels in sentences like this.

Also, vogel is a de-word:

• singular: de vogel
• plural: de vogels

In Dutch, all plural nouns take de, so de vogels is correct.

Because the subject is plural:

• de vogels = the birds

Plural subjects take the plural verb form:

• de vogel zingt = the bird sings
• de vogels zingen = the birds sing

So zingen is correct because there is more than one bird.

Vroeg means early.

It functions as an adverb and tells you when your sister wakes up.

So the structure is roughly:

• Mijn zus = subject
• wordt ... wakker = wakes up
• vroeg = early
• als de vogels zingen = when the birds sing

Dutch places vroeg before wakker here very naturally:

• Mijn zus wordt vroeg wakker.

That is the normal word order.

Because Dutch idiom often uses wakker worden as the standard expression for waking up.

So:

• vroeg wakker worden = to wake up early

Even though English uses wake up as a verb plus particle, Dutch prefers the idea of becoming awake.

This is one of those places where a word-for-word comparison with English is less helpful than learning the whole chunk:

• wakker worden
• laat wakker worden
• vroeg wakker worden

Yes, but it means something slightly different.

• Mijn zus wordt vroeg wakker = she wakes up early
• Mijn zus is vroeg wakker = she is awake early

So:

• wordt wakker focuses on the moment or process of waking up
• is wakker focuses on the state of already being awake

That is an important distinction.

Compare:

• Hij wordt om zes uur wakker. = He wakes up at six.
• Hij is om zes uur al wakker. = He is already awake at six.

Most likely it describes a habitual or repeated situation.

The present tense in Dutch often works this way, especially with als:

• Mijn zus wordt vroeg wakker als de vogels zingen.

This sounds like:

• whenever the birds sing, she wakes up early
• this is something that generally happens

So even though the verbs are in the present tense, the meaning is not necessarily about only one single moment happening right now.

The sentence has two parts:

1. Main clause: Mijn zus wordt vroeg wakker
2. Subordinate clause: als de vogels zingen

The main clause follows the usual Dutch verb-second pattern:

• Mijn zus = first element
• wordt = finite verb in second position
• vroeg wakker = rest of the predicate

Then the subordinate clause begins with als, and inside that clause the verb goes to the end:

• als
• de vogels
• zingen

So the overall pattern is:

• [main clause with verb second] + [subordinate clause with verb final]

That is a very common Dutch sentence structure.