Learn Hardcore German: Könntest du bitte im Posteingang nachschauen, ob meine E-Mail angekommen ist? - Could you please check in the inbox whether my email has arrived?

Könntest du uses the subjunctive (Konjunktiv II) to make the request softer and more polite—like English could you.
Kannst du is more direct—like can you. It’s fine with friends/peers but a bit less courteous.
Konntest du is simple past of können and usually means were you able to (in the past), not a polite request in the present.
Alternatives: Würdest du (bitte) …? is also a common polite request. Adding softeners like mal, kurz, or vielleicht can further soften the tone: Könntest du mal kurz …?

What does im mean here, and why not in den?

im = contraction of in dem (dative case).
in is a two-way preposition: it takes
- dative for location (where?): im Posteingang = in the inbox.
- accusative for movement (into where?): in den Posteingang verschieben = move it into the inbox.
Here we’re talking about looking in a place (location), so dative is right: im Posteingang.

What are the genders and cases in this sentence?

der Posteingang (masculine). Dative singular after in (location): in dem Posteingang → im Posteingang.
die E-Mail (feminine). In the ob-clause it’s the subject, so nominative: meine E‑Mail.
The finite verb in the ob-clause agrees with the subject: meine E‑Mail … ist.

Why is there a comma before ob?

ob introduces a subordinate clause (an indirect yes/no question), and German requires a comma before subordinate clauses.
Pattern: Main clause, comma, ob-clause.
- Könntest du bitte …, ob … ist?

Why ob and not wenn or falls?

ob = whether (introduces an indirect yes/no question).
- … nachschauen, ob meine E‑Mail angekommen ist.
wenn/falls = if (condition).
- Wenn/Falls die E‑Mail angekommen ist, sag mir bitte Bescheid. Using wenn/falls in the original sentence would change the meaning.

Why is it angekommen ist at the end? Could it be ist angekommen?

In a subordinate clause, the finite verb goes to the end. With the perfect tense, you get a verb cluster at the end.
Standard order here: participle + auxiliary → angekommen ist.
… ob meine E‑Mail angekommen ist is standard; … ob meine E‑Mail ist angekommen is nonstandard.

Why ist and not hat with angekommen?

ankommen is an intransitive verb of motion/arrival, and such verbs typically use sein in the perfect tense.
Examples: Er ist angekommen., Sie ist gegangen., Es ist passiert.

Is nachschauen a separable verb, and why isn’t it split here?

nachschauen is separable (nach + schauen).
- As a main verb: Schau bitte im Posteingang nach. (split)
- With a modal (as an infinitive): the infinitive sits at the end and isn’t split: Könntest du … nachschauen?

What’s the nuance difference between nachschauen, nachsehen, nachgucken, prüfen, and checken?

nachschauen / nachsehen: neutral, everyday “have a look/check.” nachsehen may sound a touch more standard.
nachgucken: colloquial/regional (esp. northern/colloquial).
prüfen / überprüfen: more thorough or formal “examine/verify.”
checken: very colloquial/anglicism “to check.” All work here, with register differences: Könntest du bitte im Posteingang nachsehen/prüfen/checken …

Can I move bitte around? Does position change the tone?

Common placements:
- Könntest du bitte im Posteingang nachschauen … (neutral polite)
- Bitte, könntest du … (extra polite/emphatic at the start)
- Könntest du mal kurz im Posteingang nachschauen, bitte? (sentence-final bitte is possible, slightly more emphatic; still fine) Position mainly affects nuance/emphasis; all are acceptable.

How do I make this formal (Sie)?

Könnten Sie bitte im Posteingang nachschauen, ob meine E‑Mail angekommen ist? Use capital Sie (and corresponding verb ending -en) for formal address.

Should I add bei dir: ob meine E-Mail bei dir angekommen ist?

Optional. bei dir makes the recipient explicit: … ob meine E‑Mail bei dir angekommen ist.
Without it, angekommen in context already implies “in your inbox,” especially with im Posteingang earlier, so it’s usually unnecessary.

Is angekommen the best verb for emails? What about eingegangen or zugegangen?

angekommen: very common and natural in everyday speech for emails.
eingegangen: a bit more technical/formal, tied to the idea of “entry” into a system or inbox; perfectly fine: … ob meine E‑Mail eingegangen ist.
zugegangen: legal/formal register (has reached the sphere of control of the recipient).
Colloquial alternatives: … ob du meine E‑Mail bekommen/erhalten hast.

Is E-Mail with a hyphen required? Is Email wrong?

Standard spelling is E‑Mail (with hyphen). Plural: E‑Mails.
Email (without hyphen) can mean “enamel” in German; many people still write Email, but E‑Mail is the recommended spelling in standard orthography.
Colloquially, Mail is also common: meine Mail.

Any pronunciation tips for tricky sounds here?

ö in Könntest: rounded vowel; like the vowel in British English “bird,” but with lips rounded.
ch in nach: the “ach” sound (like Scottish “loch”).
sch in schauen: like English “sh.”
E‑Mail: say the letter E plus “mail” (roughly “ee-mail”).
Main stress: KÖNNTES(t), NÁCHschauen, Pósteingang, É‑Mail, angekómmen.

Could I use the simple past: ob meine E-Mail ankam?

Yes, grammatically fine. … ob … ankam (preterite) is more likely in formal writing or narratives.
In everyday spoken German, the perfect (… angekommen ist) is preferred.

Do I have to mention im Posteingang, or can I omit it?

You can omit it: Könntest du bitte nachschauen, ob meine E‑Mail angekommen ist? Context usually makes “in your inbox” clear.
Keep im Posteingang if you want to be explicit (e.g., distinguishing from spam or other folders).