Learn Hardcore German: Der Fleißige bleibt im Büro und arbeitet weiter. - The diligent one stays in the office and keeps working.

fleißig = hard-working / diligent (adjective)
When an adjective is turned into a noun referring to a person, German:
- capitalizes it: Fleißige
- adds an article: der
- gives it an ending: -e → Fleißige

So Der Fleißige doesn’t name a specific noun like Mann or Mitarbeiter; it stands in for “the hard-working person (male)” and is understood from context. This is called a nominalized adjective (substantiviertes Adjektiv).

Why is Fleißige capitalized and why does it end in -e?

Two reasons:

Capitalization
In German, all nouns are capitalized. When an adjective is used as a noun (nominalized), it is treated like a noun and is capitalized:
- fleißig (adjective in normal use)
- der Fleißige (nominalized adjective → noun)
Ending -e
After the definite article der, the adjective (here: now acting as a noun) takes the weak ending -e in nominative singular masculine:
- der fleißige Mann
  → dropping Mann but keeping the form: der Fleißige

So Der Fleißige follows the same declension pattern as der fleißige Mann, just without the explicit noun.

Why is the article der used with Fleißige? Could it also be die or das?

Der shows that we’re talking about a masculine singular person: “the hard-working (man / guy / male employee)”.

With nominalized adjectives, the article chooses gender and number:

Masculine: der Fleißige – “the hard-working man (guy, male worker)”
Feminine: die Fleißige – “the hard-working woman”
Plural (any gender mix): die Fleißigen – “the hard-working ones”

So yes, you can have die Fleißige, das Fleißige (for a neuter thing, although that’s less typical with this adjective), and die Fleißigen; it depends on who or what you’re referring to.

Why is it bleibt and not ist in „Der Fleißige bleibt im Büro …“?

bleiben means “to stay / to remain”, not just “to be”.

ist im Büro = “is in the office” (just describes the location)
bleibt im Büro = “stays in the office” / “remains in the office” (focus on not leaving)

In this sentence, the meaning is that others might go home or leave, but this person stays there and keeps working. Using ist would lose that “not leaving / remaining” idea.

Why is it im Büro and not ins Büro or in das Büro?

im Büro is a contraction of in dem Büro and uses the dative case.

With in, the case depends on whether it’s about location (where?) or movement (where to?):

Location (Wo?) → dative
- Er bleibt im Büro. = He stays in the office. (no movement)
Movement (Wohin?) → accusative
- Er geht ins Büro. = He goes into the office.

Here, bleiben is about staying somewhere (no change of location), so we use dative:
im Büro (= in dem Büro), not ins Büro (= in das Büro).

What exactly does weiter add to arbeitet? How is arbeitet weiter different from just arbeitet?

arbeiten = to work.
weiter means “further / on / continue” in this context.

Er arbeitet. = He is working. (just a fact)
Er arbeitet weiter. = He keeps working / continues working.

So arbeitet weiter emphasizes that the action goes on, usually after a point where stopping might be expected (e.g. others are done, time is up, etc.).

Is weiterarbeiten a single verb? How does it behave in other sentence structures?

Yes. weiterarbeiten is a separable verb (trennbares Verb):

infinitive: weiterarbeiten
finite present: it splits: arbeitet weiter

Examples:

Main clause (present):
- Er arbeitet weiter. – He continues working.
With a modal verb (infinitive at the end):
- Er will weiterarbeiten. – He wants to continue working.
Perfect tense (the ge goes in the middle):
- Er hat weitergearbeitet. – He has continued working.
Subordinate clause (verb at the end, unsplit):
- …, weil er weiterarbeitet. – …because he continues working.

So: in main clauses without extra verbs, it appears split (arbeitet weiter); in non-finite forms or at the end of subordinate clauses, it stays together (weiterarbeiten, weiterarbeitet, weitergearbeitet).

Why is the verb in second position in Der Fleißige bleibt im Büro … and also after und in … und arbeitet weiter?

German main clauses generally follow the V2 rule: the conjugated verb is in second position.

First clause:
- Der Fleißige (position 1, the subject)
- bleibt (position 2, the verb)
- im Büro (rest of the sentence)
Coordinated clause with und:
After und, you start a new main clause, so V2 applies again:
- und (coordinating conjunction, outside the counting)
- arbeitet (now position 2 in the new clause)
- weiter (rest)

So the structure is:
[Der Fleißige] [bleibt] [im Büro] und [arbeitet] [weiter].
Both bleibt and arbeitet are in second position in their respective main clauses.

Could we move im Büro or change the word order? For example: „Der Fleißige arbeitet im Büro weiter.“

Yes, German word order is relatively flexible as long as the V2 rule is respected. Possible variants:

Der Fleißige bleibt im Büro und arbeitet weiter. (neutral)
Der Fleißige bleibt im Büro und arbeitet dort weiter. (adds “there”)
Der Fleißige arbeitet im Büro weiter.
Im Büro bleibt der Fleißige und arbeitet weiter. (emphasis on im Büro)

They’re all grammatical, but the focus changes:

Starting with Im Büro … stresses the location.
Putting weiter right after arbeitet is the most common for the separable verb in a main clause:
- arbeitet weiter im Büro is also possible, but focuses slightly more on the continuity first, then adds the place.

Why is there ß in Fleißige and not ss? How is it pronounced?

ß (called Eszett or scharfes S) is used in standard German:

after long vowels or diphthongs (like ei, au, eu)
in the middle or end of a word

Fleißige comes from Fleiß (diligence), pronounced with a long ei sound: [flaɪ̯sɪɡə] (roughly FLY-si-guh).

Pronunciation rule here:

ei = like English “eye”
ß = like “s” in “see” (never like “z”)

So Fleißige sounds like “FLY-si-guh”, and the ß just ensures you know the vowel before it is long.