Learn Hardcore Dutch: Anna merkt dat ze minder gestrest is wanneer ze elke dag even wandelt voordat ze gaat studeren. - Anna notices that she is less stressed when she takes a short walk every day before she starts studying.

You could say just Anna merkt het (Anna notices it), but then you lose the explanation of what she notices. The dat-clause gives the content of what she notices, just like in English:

Anna notices that she is less stressed.

Why is it ze and not zij?

Dutch has two forms for “she”:

ze – unstressed form (neutral, most common in the middle of a sentence)
zij – stressed form (used for emphasis or contrast)

In this sentence, we’re just stating facts, not emphasizing the subject:

Anna merkt dat ze minder gestrest is …
→ ze is the normal, unstressed pronoun here.

You would use zij mainly when you want to contrast or stress:

Niet ik, maar zij is minder gestrest.
Not me, but *she is less stressed.*

Why is the verb at the end in dat ze minder gestrest is and wanneer ze elke dag even wandelt voordat ze gaat studeren?

Dutch word order changes in subordinate clauses (clauses introduced by words like dat, wanneer, voordat, omdat, etc.).

Rule of thumb:

Main clause: verb in second position (V2).
Subordinate clause: conjugated verb goes to the end.

In the sentence:

Anna merkt – main clause → merkt is in second position.
dat ze minder gestrest is – subordinate clause (because of dat) → is goes to the end.
wanneer ze elke dag even wandelt voordat ze gaat studeren – also a subordinate clause (because of wanneer) → main verb wandelt is at the end.
Inside that, voordat ze gaat studeren is again a subordinate clause → gaat studeren goes to the end.

So:

Main: Anna merkt …
Subordinate: dat ze minder gestrest is
Subordinate: wanneer ze elke dag even wandelt
Subordinate inside that: voordat ze gaat studeren

What exactly does minder gestrest mean, and why gestrest and not gestresseerd?

Minder gestrest literally means less stressed.

minder = less (comparative of “little/few” or “not as much”)
gestrest = stressed (adjective, from the noun stress)

So minder gestrest = less stressed.

About gestrest vs gestresseerd:

gestrest – the most common, everyday word, informal-neutral.
gestresseerd – more formal or slightly bookish; also correct, but less common in casual speech.

Both are understood and grammatically fine:

ze is minder gestrest
ze is minder gestresseerd

Learners will mostly encounter gestrest in spoken Dutch and in informal writing.

Why is it wanneer here and not als or toen?

Dutch has several words for “when”:

wanneer – when (general, often in questions or more formal/written language)
als – when / if (for repeated or conditional situations)
toen – when (for a single event in the past)

In this sentence, we talk about a general, repeated situation (every day), not one specific moment in the past:

wanneer ze elke dag even wandelt
= when she takes a walk every day (habitual)

In everyday spoken Dutch, many people would also say:

… als ze elke dag even wandelt …

Toen would be wrong here, because that’s used for one-time past events:

Toen ze gisteren even wandelde, was ze minder gestrest.
When she took a walk yesterday, she was less stressed.

What does even mean in elke dag even wandelt? Is it necessary?

Even is a very common little word in Dutch; it’s often hard to translate directly. Here, it adds a nuance like:

for a short while
briefly
just (for a bit)

So elke dag even wandelt suggests:

takes a (short) walk every day
goes for a quick walk every day

Without even, the sentence is still correct:

… wanneer ze elke dag wandelt …

But even makes it sound lighter, more casual, and emphasizes that it’s not a long or big activity, just a little daily walk.

Why is it wandelt and not loopt?

Both verbs involve moving on foot, but they are used differently:

wandelen = to go for a walk, to take a walk (often recreational, relaxed)
lopen = to walk (as a way of moving), also sometimes to run/operate (machines, processes), etc.

In this sentence, the idea is that Anna takes a walk for relaxation:

… wanneer ze elke dag even wandelt …
→ suggests a deliberate, maybe pleasant walk for her well-being.

If you said:

wanneer ze elke dag even loopt

it would sound more like “when she walks a bit every day” without clearly suggesting “going for a walk” as an activity. Wandelen is the more natural choice for “go for a walk” in this context.

Why is it voordat ze gaat studeren and not voor ze gaat studeren? Are both correct?

Both are correct:

voordat = before (subordinating conjunction)
voor
- clause (in spoken Dutch) is often used instead of voordat

In standard written Dutch, voordat is preferred before a clause:

voordat ze gaat studeren – most standard/formal.

In everyday speech, many people say:

voor ze gaat studeren

So:

Anna merkt dat ze minder gestrest is wanneer ze elke dag even wandelt voordat ze gaat studeren.
= formally perfect.
… wandelt voor ze gaat studeren.
= very natural in speech, still fine in writing, just a bit more informal.

Why do we say gaat studeren instead of just studeert?

Gaan + infinitive often expresses:

future: going to do something
planned or intended action

Here:

voordat ze gaat studeren
= before she goes to study / before she starts studying

You could also say:

voordat ze studeert

That’s grammatically okay, but gaat studeren sounds more natural for the idea of “before she starts studying” as a daily activity starting at a certain moment.

Nuance:

voordat ze studeert – more abstract/general.
voordat ze gaat studeren – more like “before she (actually) begins studying (today / each day)”.

Why is the verb tense present in is, wandelt, gaat studeren when we’re talking about a general habit?

Dutch uses the present tense for:

actions happening now
regular habits
general truths

This is the same as in English:

Anna merkt dat ze minder gestrest is
Anna notices that she is less stressed.
wanneer ze elke dag even wandelt
when she takes a short walk every day
voordat ze gaat studeren
before she (goes to) study / studies

So the present tense here expresses a repeated, habitual situation, not just something happening exactly at this moment.

Could you change the order of elke dag and even in wanneer ze elke dag even wandelt?

A little, but not freely. The natural order is:

wanneer ze elke dag even wandelt

You can sometimes put even directly after the verb for a slightly different emphasis:

wanneer ze elke dag wandelt, even voordat ze gaat studeren (but this changes the structure and sounds clumsy in this sentence)

What you normally wouldn’t say is:

✗ wanneer ze even elke dag wandelt (unnatural order)

In practice, keep:

elke dag (time expression) before the verb,
even right before the verb: elke dag even wandelt.

That’s the most natural and idiomatic.

Why is it minder gestrest is and not minder gestrest was after merkt dat?

Dutch doesn’t always do “sequence of tenses” the same way English does.

Anna merkt dat ze minder gestrest is
= Anna notices that she is less stressed.
→ She’s noticing a current state.

If you say:

Anna merkte dat ze minder gestrest was
= Anna noticed that she was less stressed.
→ Both noticing and being less stressed are in the past.

So the tense in the dat-clause (is / was) depends on when the state is true, not automatically on the tense of merkt/merkte. Here, we are talking about her present habit and present state, so is is correct.