Learn Hardcore German: Die Chefin gibt mir morgen Bescheid, ob die Besprechung um neun Uhr stattfindet. - The boss will let me know tomorrow whether the meeting takes place at nine o’clock.

German commonly uses the present tense for near-future events when a time expression (like morgen) makes the timing clear. You could also use the future:

Present (very common): Die Chefin gibt mir morgen Bescheid …
Future I (also correct): Die Chefin wird mir morgen Bescheid geben … The meaning is the same; the future can sound a bit more formal or emphatic.

Why is it ob and not wenn, falls, or dass?

ob introduces an indirect yes/no question (“whether”). That’s exactly what follows here.
wenn/falls express conditions (“if/in case”), not “whether.”
dass introduces a “that”-clause, not a yes/no alternative. Examples:
Sie sagt mir, ob die Besprechung stattfindet. (She tells me whether it takes place.)
Wenn/Falls die Besprechung stattfindet, … (If it takes place, …)
Sie sagt mir, dass die Besprechung stattfindet. (She tells me that it takes place.)

Why is there a comma before ob?

German requires a comma before subordinate clauses. ob die Besprechung um neun Uhr stattfindet is a subordinate clause, so a comma is mandatory.

Why does stattfindet go to the end of the clause?

In subordinate clauses, the finite verb goes to the end. With separable verbs like stattfinden, the prefix reattaches in subordinate clauses:

Main clause: Die Besprechung findet um neun Uhr statt.
Subordinate: …, ob die Besprechung um neun Uhr stattfindet.

Could I use ist or passiert instead of stattfindet?

stattfinden is the standard verb for scheduled events (“to take place”).
sein can work in simple schedules: Das Meeting ist um neun. (OK)
passieren means “to happen,” usually for incidents/accidents, not scheduled meetings.
Es gibt ein Meeting um neun is also possible (“There is a meeting at nine”), but it presents the existence of a meeting, not the occurrence of a specific, already-known one.

Why is it mir and not mich?

Because of the verb pattern: jemandem Bescheid geben (“to let someone know”). The person is in the dative case:

Dative (to whom?): mir
Accusative (what?): Bescheid (the thing being given)

Why is there no article before Bescheid?

In the idiom Bescheid geben/sagen, Bescheid is used without an article:

jemandem Bescheid geben/sagen = to let someone know. When Bescheid means an official written notice, it takes an article:
Ich habe den/ einen Bescheid vom Amt bekommen.

What’s the difference between Bescheid geben, Bescheid sagen, and Bescheid wissen?

jemandem Bescheid geben/sagen: tell/let someone know. geben can feel slightly more formal; sagen is very common in everyday speech.
Bescheid wissen (über …): to be informed/aware (about …). Examples:
Kannst du mir morgen Bescheid sagen/geben?
Ich weiß darüber Bescheid.

Does die Chefin mean a cook (“chef”)?

No. False friend alert:

der Chef / die Chefin = the boss.
der Koch / die Köchin = the cook/chef (profession in a kitchen).

Why is it um neun Uhr, not am neun Uhr?

um is used for exact clock times: um neun (Uhr), um 14:30 Uhr. It governs the accusative.
am is used for days/dates or parts of the day: am Montag, am 9. Januar, am Morgen.

Can I write um neun or um 9 without Uhr?

Yes, in speech and informal writing um neun or um 9 is fine. In careful writing, um neun Uhr or um 9 Uhr is standard. Uhr is capitalized because it’s a noun.

Can I start the sentence with Morgen?

Yes. German main clauses are verb-second:

Morgen gibt mir die Chefin Bescheid, … You can also keep the original:
Die Chefin gibt mir morgen Bescheid, … Putting morgen at the very end (… Bescheid, morgen) sounds odd.

Why does mir come before morgen?

Pronouns tend to appear early in the middle field of a German clause. A natural order is:

subject > (object pronouns) > time > other elements. Hence: Die Chefin gibt mir morgen Bescheid (not: … gibt morgen mir …).

How would the sentence look with the future tense?

Most natural: Die Chefin wird mir morgen Bescheid geben, ob die Besprechung um neun Uhr stattfindet. You can also make the subordinate clause future:
…, ob die Besprechung um neun Uhr stattfinden wird. Both are grammatical; present in the subordinate clause is typically preferred for scheduled events.

What’s the nuance of Besprechung vs. Sitzung, Meeting, Treffen?

die Besprechung: a business discussion/meeting (very common).
die Sitzung: a formal session (committee/board, often with agenda/minutes).
das Meeting: loanword, businessy and neutral-informal.
das Treffen: a meeting/get-together between people, not necessarily formal.

What’s the difference between morgen, am Morgen, and morgens?

morgen: tomorrow.
am Morgen: in the morning (on a particular day).
morgens: in the mornings, usually/every morning (habitual).

Can the subordinate clause with ob be placed first?

Yes: Ob die Besprechung um neun Uhr stattfindet, gibt mir die Chefin morgen Bescheid. This is grammatical and stylistically marked (more written or for emphasis). The original order is more neutral.

How can I say “whether or not” or give two options with ob?

“Whether or not”: Die Chefin gibt mir morgen Bescheid, ob die Besprechung um neun Uhr stattfindet oder nicht.
Two alternatives: …, ob die Besprechung um neun oder um zehn Uhr stattfindet.