Learn Hardcore Dutch: De andere spelers zijn geen verliezers, want zij hebben veel geleerd. - The other players are not losers, because they have learned a lot.

de andere spelers = the other players (a specific group you and the listener know about)
andere spelers (without de) would usually mean other players in a more general, non‑specific sense.

Because the sentence contrasts these players with some players that were just mentioned (for example, the winners), we are talking about those particular other players, so Dutch needs the definite article de.

What exactly does andere mean here, and where does it go in the phrase?

Andere means other. It is an adjective modifying spelers.

Word order in Dutch noun phrases is similar to English:

de andere spelers
- de = the (definite article)
- andere = other (adjective)
- spelers = players (noun)

So the order is: article + adjective + noun, just like the other players in English.

How do I know that zij means they here and not she?

Zij can mean both she and they, depending on context.

Here you can see it must mean they because:

It refers back to de andere spelers (plural).
The verb is hebben (plural they have), not heeft (she has).

So:

zij hebben = they have
zij heeft = she has

The combination zij + hebben clearly shows it is plural: they.

What is the difference between zij and ze?

Both zij and ze can mean they (and zij can also mean she).

zij is the stressed form.
ze is the unstressed form.

You usually use zij:

for contrast or emphasis: Zij hebben veel geleerd, niet wij. (They learned a lot, not us.)
at the beginning of a sentence when you want to highlight the subject a bit more.

You often use ze in more neutral, flowing speech:

Ze hebben veel geleerd.

In this sentence, zij at the start of the clause is slightly more emphatic than ze, but both would be grammatically correct:
… want zij hebben veel geleerd / … want ze hebben veel geleerd.

Why is it geen verliezers and not niet verliezers?

Dutch uses geen instead of niet when you negate a noun with no article (or when you would otherwise use een).

Think of it this way:

zij zijn verliezers = they are losers
zij zijn geen verliezers = they are not losers

You cannot say zij zijn niet verliezers here; that sounds wrong in Dutch.

General rule:

geen negates a thing / noun (often where you could have een):
- Ik heb een auto. → Ik heb geen auto.
niet negates verbs, adjectives, adverbs, or specific noun phrases with a definite article:
- Zij komt niet. (She is not coming.)
- Dat is niet de winnaar. (That is not the winner.)

In this sentence, verliezers is a bare plural noun (no article), so you use geen.

What tense is hebben geleerd, and what does it correspond to in English?

Hebben geleerd is the present perfect tense in Dutch.

Structure:

hebben (present tense auxiliary: to have)
geleerd (past participle of leren = to learn)

It roughly corresponds to English have learned / have learnt:

zij hebben veel geleerd ≈ they have learned a lot

Dutch tends to use the present perfect tense much more frequently than English does in everyday speech, often where English might use the simple past:

Dutch: Gisteren hebben zij veel geleerd.
English: Yesterday they learned a lot. (simple past)

Why is it hebben veel geleerd and not veel hebben geleerd?

The word order here follows the normal main-clause pattern: finite verb in second position.

In the clause:

zij hebben veel geleerd

The order is:

zij (subject)
hebben (finite verb, 2nd position)
veel geleerd (rest of the predicate: object/adverb + past participle)

If you move veel in front of hebben in a main clause:

zij veel hebben geleerd

this sounds wrong in Dutch, because then hebben would not be in the second position anymore.

However, in a subordinate clause with a subordinator like omdat, the order changes and you can get:

omdat zij veel hebben geleerd

Here the finite verb hebben goes to the end of the clause (after veel and before geleerd), which is correct in subordinate clauses.

What does want mean here, and what does it do to the word order?

Want means because (in a more informal, explanatory way).

It is a coordinating conjunction, like English and, but, or. This means:

The clause after want keeps normal main-clause word order (finite verb in second position).

So:

Zij zijn geen verliezers, want zij hebben veel geleerd.
- zij (subject)
- hebben (finite verb, in 2nd position)
- veel geleerd (rest)

Compare that with omdat (a subordinating conjunction):

Zij zijn geen verliezers, omdat zij veel hebben geleerd.
- Here hebben moves to the end of the clause: … omdat zij veel hebben geleerd.

So:

want → main clause word order (verb in 2nd position):
- want zij hebben veel geleerd
omdat → subordinate clause word order (verbs at the end):
- omdat zij veel hebben geleerd

Can I drop zij and just say … want hebben veel geleerd?

No, you generally cannot drop the subject pronoun in Dutch the way you sometimes can in languages like Spanish or Italian.

You must keep zij:

… want zij hebben veel geleerd.

Leaving it out:

… want hebben veel geleerd.

sounds ungrammatical in standard Dutch (except in very special, telegraphic styles like headlines or notes).

How are spelers and verliezers formed, and what do the endings mean?

Both spelers and verliezers are plural nouns formed from verbs:

spelen (to play) → speler (player) → spelers (players)
verliezen (to lose) → verliezer (loser) → verliezers (losers)

Pattern:

Verb + -er → agent noun (person who does the action)
Add -s for the plural.

So:

spelen → speler = someone who plays
verliezen → verliezer = someone who loses

Why is the verb zijn used with geen verliezers?

Zijn is the verb to be, and here it links the subject to a noun phrase that describes what the subject is (or is not):

De andere spelers zijn geen verliezers.
- De andere spelers = subject
- zijn = are
- geen verliezers = noun phrase describing what they are not

This works just like English:

The other players are not losers.

So zijn is a linking verb (copula) connecting the subject with the description / classification.