Learn Hardcore German: Die Lieferung kommt innerhalb von zwanzig Minuten. - The delivery will arrive within twenty minutes.

German often uses the present tense (Präsens) for near-future events when a time expression makes the timing clear. So Die Lieferung kommt innerhalb von zwanzig Minuten naturally means “will arrive within twenty minutes.” You could also say Die Lieferung wird innerhalb von zwanzig Minuten kommen, but the present is shorter and very common.

Should I use ankommen instead of kommen here?

Both are possible:

Die Lieferung kommt innerhalb von zwanzig Minuten. (idiomatic and common)
Die Lieferung kommt innerhalb von zwanzig Minuten an. or … wird innerhalb von zwanzig Minuten ankommen. (explicitly “arrive”) Using ankommen emphasizes the moment of arrival; plain kommen is perfectly idiomatic with deliveries.

What case follows innerhalb (von), and why is von there?

Traditionally, innerhalb governs the genitive: innerhalb dreier Tage. In modern standard German, especially with numbers, you almost always use the pattern innerhalb von + dative: innerhalb von zwanzig Minuten. Here, von takes the dative, so Minuten is dative plural.

Can I drop von and say innerhalb zwanzig Minuten?

Not in normal speech. The genitive with numbers would be innerhalb zweier Minuten / dreier Minuten, which sounds formal or old-fashioned. With larger numbers like 20, use innerhalb von zwanzig Minuten.

What’s the difference between innerhalb von zwanzig Minuten and in zwanzig Minuten?

innerhalb von zwanzig Minuten = within twenty minutes (any time up to the 20-minute mark; no later than 20 minutes).
in zwanzig Minuten = in twenty minutes (roughly at the 20-minute point, not earlier). In everyday talk, people do say in 20 Minuten loosely, but if you want to be precise about the “no later than” idea, use innerhalb von or spätestens in.

Where can the time phrase go in the sentence?

You can front it for emphasis, but keep verb-second:

Innerhalb von zwanzig Minuten kommt die Lieferung.
Die Lieferung kommt innerhalb von zwanzig Minuten. In both, the finite verb kommt stays in second position in the clause.

Why Minuten and not Minute?

Because zwanzig is plural. Also, after von, you need the dative; the dative plural of most nouns ends in -n. Minute already forms its plural with -n, so dative plural is also Minuten. (Compare: drei Tage → von drei Tagen.)

What gender is Lieferung, and why die?

Lieferung is feminine, so the nominative singular article is die: die Lieferung. If you meant “a delivery,” you’d say eine Lieferung. Plural is die Lieferungen: Die Lieferungen kommen …

How do I pronounce tricky parts like zwanzig and von?

z in zwanzig = [ts], w = [v], final -ig is commonly [ɪç] (like the end of ich), so roughly “ts-VAN-tsiCH.”
von starts with an f sound (German v often = [f]), so “fon.”
ie in Die is a long “ee.”

Are there shorter or alternative expressions to innerhalb von?

binnen zwanzig Minuten (a bit formal/concise).
spätestens in zwanzig Minuten to stress “no later than.”
Plain in zwanzig Minuten is common but, strictly speaking, means “in twenty minutes (from now).”

If I want to include the place with ankommen, which prepositions do I use?

With ankommen, use:

in + dative for cities/countries/buildings: Die Lieferung kommt in Berlin an.
an + dative for specific points: … am Bahnhof an.
bei + dative for people/firms: … bei mir / bei der Firma an.

Is it okay to write numbers as digits or abbreviate minutes?

Yes. Both zwanzig Minuten and 20 Minuten are fine. The common abbreviation is 20 Min. (with a period).