Learn Hardcore German: Die Sprechstunde findet teilweise online statt, und das Wartezimmer ist leer. - The consultation takes place partly online, and the waiting room is empty.

With doctors: the consultation hours.
At universities: a professor’s office hours. Singular vs plural: die Sprechstunde (a specific session), die Sprechstunden (multiple sessions or regular hours). Related but different: Sprechzeiten = the published opening times (schedule), not the event itself.

Why is it findet … statt and not one word here?

Because stattfinden is a separable verb. In a main clause, the conjugated part (findet) is in second position and the separable prefix (statt) goes to the end:

Main clause: Die Sprechstunde findet … statt.
Subordinate clause: …, dass die Sprechstunde … stattfindet. (now written together at the end)
Perfect: Die Sprechstunde hat … stattgefunden. (past participle is one word)

Which auxiliary verb does stattfinden use in the perfect, and what are the key forms?

It takes haben, not sein.

Perfekt: hat stattgefunden
Präteritum (simple past): fand statt
Infinitive: stattfinden
Infinitive with zu: stattzufinden

Could I just say “Die Sprechstunde findet online” without statt?

No. For “an event takes place,” German needs stattfinden. Say:

Die Sprechstunde findet online statt. If you avoid the verb, you need a different structure, e.g. Die Sprechstunde ist online verfügbar, but that slightly changes the meaning.

Where should teilweise go, and are there good alternatives?

Degree adverbs like teilweise typically come before the main content adverb:

Natural: Die Sprechstunde findet teilweise online statt.
Alternatives:
- Die Sprechstunde findet zum Teil online statt.
- Die Sprechstunde findet teils online, teils vor Ort statt. (nice for a “partly/partly” contrast) “Online teilweise” sounds odd.

How do I say the opposite (not online / canceled)? Where does nicht go?

Not online: Die Sprechstunde findet nicht online statt.
Does not take place (canceled): Die Sprechstunde findet nicht statt. If you mean “partly not online,” it’s clearer to say: teils online, teils vor Ort rather than teilweise nicht online.

Is the comma before und required here?

It’s optional. German allows a comma between two independent main clauses linked by und to improve clarity. So both are fine:

With comma: …, und das Wartezimmer ist leer.
Without comma: … und das Wartezimmer ist leer.

What are the genders and plurals of Sprechstunde and Wartezimmer?

die Sprechstunde (feminine), plural: die Sprechstunden
das Wartezimmer (neuter), plural: die Wartezimmer (no change in the plural form)

Why is leer uninflected here, and when would it take an ending?

After the copula sein, predicate adjectives stay uninflected: Das Wartezimmer ist leer. As an attributive adjective before a noun, it takes an ending: das leere Wartezimmer, ein leeres Wartezimmer, die leeren Wartezimmer.

Does leer mean “no people” or “no furniture”?

Context decides. Leer can mean “empty of people,” “empty of items,” or “vacant.” Here it most naturally means “no people are waiting.” For real-estate “standing empty,” you may also see leerstehend.

How would I turn this into a subordinate clause?

Move the conjugated verb to the end (and rejoin the separable verb):

…, weil die Sprechstunde teilweise online stattfindet. You can also do a causal two-clause version with a sentence adverb:
Die Sprechstunde findet teilweise online statt; deshalb ist das Wartezimmer leer.

Is online capitalized? How about in compounds?

As a standalone adverb/adjective: lowercase (online).
In compounds, standard spelling uses a capital O: die Online-Sprechstunde or die Onlinesprechstunde. Both hyphenated and solid forms are common in modern usage.

Can I reverse the clause order?

Yes:

Das Wartezimmer ist leer, und die Sprechstunde findet teilweise online statt. German main clauses keep verb-second order in each clause regardless of order.

Any quick pronunciation tips for the tricky parts?

Sprech-: the “ch” is the soft sound [ç] (like in German ich).
Stunde: initial st- is pronounced [ʃt] (like “sht-”).
Wartezimmer: z = [ts]; stress roughly on Warte; final -er is a reduced [ɐ].
online: typically [ˈɔnlaɪn] in German.
leer: long [eː]; the final “r” is vocalized: [leːɐ̯].

Is there any preference between und, aber, or a causal link here?

und simply adds information.
aber would stress a contrast: …, aber das Wartezimmer ist leer (e.g., “even so”).
Causal link if that’s the intended logic: …, deshalb ist das Wartezimmer leer or …, daher ist ….

What’s a natural opposite to online in this context?

vor Ort (on site, in person): Die Sprechstunde findet teils online, teils vor Ort statt. This is idiomatic and very common.