Learn Hardcore Dutch: Tijdens het leren moet ik me goed concentreren, anders raak ik snel afgeleid. - While studying I have to concentrate well, otherwise I quickly get distracted.

Here leren isn’t functioning as a normal verb; het leren together is a kind of noun phrase, just like tijdens de les (“during the class”).

Why is it tijdens het leren and not tijdens leren?

Dutch normally needs a definite article (het) when an infinitive is used as a noun. So:

✔ tijdens het leren
✘ tijdens leren (sounds wrong/unnatural in standard Dutch)

Compare:

Het roken is verboden. – Smoking is forbidden.
Not: ✘ Roken is verboden as a noun phrase in this position (you do see Roken verboden on signs, but that is a very telegraphic style).

So het is required here to make leren into a proper noun-like expression.

Could you also say Terwijl ik leer instead of Tijdens het leren? What’s the difference?

Yes, you could say:

Terwijl ik leer, moet ik me goed concentreren…

Both are correct, but there’s a nuance:

Tijdens het leren
- Preposition tijdens
  - noun phrase het leren.
- Slightly more neutral/formal, focuses on the period/time of learning.
Terwijl ik leer
- Subordinating conjunction terwijl
  - full clause ik leer.
- More dynamic, emphasizes the activity happening at the same time.

In everyday speech, both forms are fine. The original Tijdens het leren sounds just a bit more compact and “written”.

Why does the verb come right after Tijdens het leren: Tijdens het leren moet ik… and not Tijdens het leren ik moet…?

This is the Dutch verb-second rule (V2):

In a main clause, the finite verb (here: moet) must be in second position in the sentence.

When you start with Tijdens het leren (an adverbial phrase), that whole phrase counts as position 1. Then the verb must come next:

Tijdens het leren – slot 1
moet – verb in slot 2
ik me goed concentreren – the rest of the clause

So:

✔ Tijdens het leren moet ik me goed concentreren.
✘ Tijdens het leren ik moet me goed concentreren. (ungrammatical in standard Dutch)

If you start with the subject instead, it’s:

Ik moet me goed concentreren tijdens het leren.

Why is it moet ik me goed concentreren and not just moet ik goed concentreren?

Because zich concentreren (to concentrate) is a reflexive verb in Dutch. It normally needs a reflexive pronoun:

ik concentreer me – I concentrate
jij concentreert je – you concentrate
hij/zij concentreert zich – he/she concentrates
wij concentreren ons – we concentrate

So with moeten, you still need the reflexive pronoun:

Ik moet me goed concentreren. – I have to concentrate well.
✘ Ik moet goed concentreren. – feels incomplete/wrong in standard Dutch.

(The only time you might drop the pronoun is in certain fixed instructions like even concentreren!, but that’s a very informal, elliptical style.)

Why is it me and not mij in ik moet me goed concentreren?

Dutch has unstressed and stressed object pronouns:

1st person singular object: me (unstressed), mij (stressed/emphatic)

In normal reflexive expressions, you use the unstressed form:

Ik was me. – I wash myself.
Ik vergis me. – I’m mistaken.
Ik concentreer me. – I concentrate.

Using mij here would sound very emphatic or odd:

? Ik moet mij goed concentreren. – Possible in very emphatic contexts (e.g. contrasting with other people), but not the neutral form.

So the natural version is:

Ik moet me goed concentreren.

Do you normally say je concentreren op iets? Where is op in this sentence?

Yes, the full pattern is often:

je (mij, je, zich, ons) concentreren op iets – to concentrate on something

For example:

Ik moet me goed concentreren op mijn huiswerk.
– I have to concentrate well on my homework.

In the given sentence, the object is understood from context, so op + object is simply left out:

Tijdens het leren moet ik me goed concentreren, …
– We already know it’s about whatever you’re learning/studying, so op X doesn’t need to be stated.

So it’s grammatically complete without op; the missing object is just implied.

Could you say tijdens het studeren instead of tijdens het leren? Is there a difference between leren and studeren?

You can say both, but they’re not identical:

leren
- Broad: to learn, to study, to acquire knowledge/skills.
- Can be used for school, for learning a language, learning to drive, etc.
studeren
- More specifically: to study in an academic/serious way, often associated with university-level work.

So:

Tijdens het leren – during learning (general), during my learning activity.
Tijdens het studeren – during (serious) study, during my study session.

In everyday speech about homework or revising, many people would use leren. If you’re clearly talking about university-level study, studeren is also very natural.

What exactly does anders mean here? Is it the same as English “otherwise / or else”?

Yes. In this context, anders means “otherwise / or else” and introduces what will happen if the first clause is not fulfilled:

Tijdens het leren moet ik me goed concentreren, anders raak ik snel afgeleid.
– … I must concentrate well, otherwise I quickly get distracted.

Important: anders here does not mean “different(ly)”, which it can mean in other sentences:

Doe het anders. – Do it differently.
Wil je iets anders drinken? – Do you want to drink something else?

In the original sentence, it clearly means otherwise / or else.

Why raak ik snel afgeleid and not ik raak snel afgeleid? Why the inversion?

Same verb-second rule as before.

You have two main clauses joined by a comma and anders:

Tijdens het leren moet ik me goed concentreren,
anders raak ik snel afgeleid.

In the second clause, anders is put first for emphasis (“otherwise…”). That makes anders occupy position 1, so the finite verb (raak) must be in position 2, and the subject (ik) comes after it:

✔ Anders raak ik snel afgeleid.
✔ Ik raak anders snel afgeleid. (now ik is first, so no inversion)
✘ Anders ik raak snel afgeleid. (breaks the V2 rule)

What does raak … afgeleid mean? Why use raken instead of worden or zijn?

Raken here means “to get / to end up / to become” in the sense of falling into a state, often unintentionally.

ik raak afgeleid ≈ ik word afgeleid – I get distracted.
Focus: the change from not distracted → distracted.

Compare:

Ik raak in paniek. – I get panicky / I start to panic.
Hij raakte gewond. – He got injured.

You could also say:

… anders word ik snel afgeleid. – otherwise I quickly get distracted.
… ik ben snel afgeleid. – I am easily/quickly distracted (describing a lasting characteristic).

Nuance:

raak / word afgeleid – focuses on the process of becoming distracted.
ben snel afgeleid – describes a general trait: I’m the kind of person who gets distracted quickly.

All three are grammatically fine; the original just chooses raak to stress the change that happens if you don’t concentrate.

What kind of word is afgeleid here? A participle? An adjective?

Afgeleid is originally the past participle of the separable verb afleiden:

iemand afleiden – to distract someone
past participle: afgeleid

In raak ik snel afgeleid, it functions adjectivally, describing a state:

literally: “I end up in a distracted state.”

So grammatically, you can see it as:

raken + (adjectival) past participle describing a resulting state.

This pattern is similar to English:
“I get tired”, “I get bored”.
In Dutch you can use a participle in that adjectival way: afgeleid, gespannen, vermoeid, etc.

Could you also say makkelijk afgeleid instead of snel afgeleid? What’s the difference?

Yes, both are possible, but they emphasize different things:

snel afgeleid – quickly distracted (it happens fast in time)
makkelijk afgeleid – easily distracted (it happens easily, you don’t need much to distract you)

So:

Anders raak ik snel afgeleid.
– Otherwise I quickly become distracted (e.g. after a short time).
Anders raak ik makkelijk afgeleid.
– Otherwise I (too) easily become distracted (it doesn’t take much).

Both are natural; choose the one that matches what you want to say.