Learn Hardcore German: Kein Raum war verfügbar, deshalb diskutierten wir im Flur. - No room was available, so we had our discussion in the hallway.

Use kein to negate a noun phrase without an article: kein Raum = “no room.” Use nicht to negate verbs, adjectives, adverbs, or a specific noun with an article: Der Raum war nicht verfügbar = “The room was not available.”

Why is it Kein Raum (nominative) and not Keinen Raum?

Because Raum is the subject of war. With the verb sein, the subject stays in the nominative case. Masculine nominative is kein Raum. Keinen Raum would be accusative and is wrong here.

Is Raum the right word for “room,” or should it be Zimmer?

Both can mean “room,” but:

Raum = “room/space,” often for functional rooms (e.g., meeting rooms) or abstract space.
Zimmer = a room in a house/hotel/apartment. Here, for meeting rooms or offices, Raum is natural. In a home, you’d likely say Zimmer.

What’s the difference between verfügbar and frei?

verfügbar = available (can be used), suits resources, appointments, rooms, etc.
frei = free/unoccupied. For rooms, frei is very idiomatic: Es war kein Raum frei. Both are fine here; frei sounds a bit more natural in everyday speech.

Why isn’t verfügbar declined (no ending like -er/-e)?

It’s a predicate adjective after sein, so it doesn’t take an ending: Raum war verfügbar. If it were attributive before the noun, it would: kein verfügbarer Raum.

Can I say Es war kein Raum verfügbar?

Yes. Adding the expletive es is common and often sounds more natural: Es war kein Raum verfügbar or Es war kein Raum frei.

Why use diskutierten (simple past) instead of haben diskutiert?

In written German, the simple past (diskutierten) is standard. In speech, the present perfect is more common: … deshalb haben wir im Flur diskutiert. Both are correct; war is fine in both written and spoken German.

Does diskutieren need über?

It can be used:

without an object when the topic is clear: Wir diskutierten im Flur.
with über + Akk.: Wir diskutierten über das Problem.
or (especially in formal contexts) with a direct object: Wir diskutierten den Vorschlag.

Why is it deshalb diskutierten wir and not deshalb wir diskutierten?

German main clauses are verb-second (V2). Deshalb is in first position; the finite verb (diskutierten) must be in second, so the subject (wir) follows the verb: deshalb diskutierten wir …

Is the comma before deshalb correct? Could I use a semicolon or period instead?

Yes, the comma is standard: it links two main clauses with a connector adverb. A semicolon or a period is also fine for a slightly more formal or clearer separation:

Kein Raum war verfügbar; deshalb diskutierten wir im Flur.
Kein Raum war verfügbar. Deshalb diskutierten wir im Flur.

Can I use weil instead of deshalb? What changes?

Yes, but the clause structure changes because weil is a subordinating conjunction:

Wir diskutierten im Flur, weil kein Raum verfügbar war. Meaning stays causal; with weil, the verb war goes to the end of its clause.

Are deshalb, deswegen, darum, daher, and also interchangeable? What about dann?

deshalb/deswegen/darum/daher: largely interchangeable “therefore/for that reason.” Minor style differences; darum can feel a bit more colloquial.
also in German often means “so/therefore” (and also “well…” as a filler). It’s a false friend of English “also” (“in addition” = auch).
dann = “then/after that,” temporal, not causal. Don’t use dann to mean “therefore.”

What does im in im Flur stand for, and why dative?

im = in dem (contraction). in takes dative for location (where?): im Flur. Use accusative for motion (where to?): in den Flur.

Is im Flur the only option? What about auf dem Flur, im Gang, im Korridor?

All are possible:

im Flur and auf dem Flur are both common in Germany; auf dem Flur is a set phrase in some regions.
im Gang is common in Austria/Switzerland.
im Korridor is also understood/used. Choose what fits regional style and your audience.

Where would a time expression go if I add one?

Typical order is time–manner–place. Here, with just time and place:

Kein Raum war verfügbar, deshalb diskutierten wir am Nachmittag im Flur.

Can I front elements for emphasis, like Im Flur diskutierten wir or Verfügbar war kein Raum?

Yes. You can front one element; the verb still stays in second position:

Im Flur diskutierten wir (deshalb).
Verfügbar war kein Raum. If you front im Flur, you can move deshalb later: Im Flur diskutierten wir deshalb.

Could Raum be misunderstood as “space” rather than “room”?

Potentially. Raum can mean “physical/abstract space.” Context (availability in a building) implies “room.” If you mean “space” (not enough room), use Platz: Kein Platz war verfügbar. If you want to be explicit about a meeting room, say Besprechungsraum.

Can I make it plural: Keine Räume waren verfügbar?

Yes. That means “No rooms were available,” implying multiple rooms existed but none were free. Singular Kein Raum war verfügbar speaks about the availability of any single room in general.