Learn Hardcore Norwegian: Jeg sjekker kønummeret mitt i appen mens jeg venter. - I check my queue number in the app while I wait.

I check (habitually), or
I’m checking (right now), and the context (here: mens jeg venter = while I’m waiting) strongly suggests the ongoing meaning.

What is the dictionary form (infinitive) of sjekker, and how do you conjugate it?

The infinitive is å sjekke (to check). It’s a regular verb:

å sjekke (infinitive)
jeg sjekker (present)
jeg sjekket (past)
jeg har sjekket (present perfect)

Why does it say kønummeret and not kønummer?

kønummeret is the definite form: the queue number.

et kønummer = a queue number (indefinite; neuter noun)
kønummeret = the queue number (definite)

The ending -et shows it’s neuter and definite.

Why is it kønummeret mitt and not mitt kønummer?

Both are possible, but they feel slightly different:

kønummeret mitt (common/neutral) = my queue number
This is a very typical Norwegian pattern: definite noun + possessive.
mitt kønummer (also correct) can sound a bit more emphatic or “naming” (like introducing my queue number as a concept).

So the sentence uses the most natural everyday structure.

Why is appen definite (the app) instead of en app (an app)?

Norwegian often uses the definite form when the listener can easily identify which thing you mean from context:

i appen = in the app (the relevant/known one—often your service’s app)
i en app would suggest in an app (some app, not specified)

Also, app is a common-word noun: en app, appen.

Why is it i appen—should it be på appen?

Both can appear, but they’re used differently:

i appen is most common when you mean inside/within the app interface (doing something in the app).
på appen can be used in some contexts, often closer to on the app / on the app (platform), but it’s less standard for “using features within the app.”

So Jeg sjekker … i appen is the safest, most idiomatic choice.

Why does the sentence repeat jeg twice?

Because mens jeg venter is its own clause (while I wait), and Norwegian requires an explicit subject in each clause. You can’t usually drop the subject the way you might in some other languages.

So:

Main clause: Jeg sjekker kønummeret mitt i appen
Subordinate clause: mens jeg venter

What does mens do grammatically, and does it affect word order?

mens is a subordinating conjunction meaning while. It introduces a subordinate clause, and Norwegian subordinate-clause word order is typically no inversion:

mens jeg venter (Subject jeg before verb venter)

Compare with main-clause inversion after an adverbial:

Mens jeg venter, sjekker jeg kønummeret mitt. Here, the main clause starts with Mens …, so the verb comes before the subject: sjekker jeg.

Is venter missing something—shouldn’t it be venter jeg på?

å vente can be used in two ways:

å vente = to wait (no object needed) → mens jeg venter = while I’m waiting
å vente på noe/noen = to wait for something/someone → mens jeg venter på tur = while I’m waiting for my turn

In your sentence, it’s the general “waiting” sense, so venter alone is perfectly fine.

How do you pronounce Jeg sjekker kønummeret mitt i appen mens jeg venter (especially sj, ø, and kjø)?

Key pronunciation points:

jeg: often sounds like yai or jæi (varies by dialect); the final g is usually not a hard g sound.
sjekker: sj is like the English sh sound.
kø: ø is like the vowel in French peu / German ö; it doesn’t exist in English.
kø is roughly like ker with rounded lips (approximation).
kønummeret: stress is typically on num: kø-NUM-me-ret.