Learn Hardcore German: Sie können auch am Telefon zusagen, beispielsweise noch heute. - You can also confirm by phone, for example even today.

Most likely formal you. Capitalized Sie is the polite second person. At the start of a sentence, Sie could also be they (since both take können), but context usually makes it clear. In instructions or customer info, it almost always means formal you.

Why is können in second position and zusagen at the end?

German main clauses follow the verb-second rule: the conjugated verb (können) is in position 2. Non-finite verbs (infinitives, participles) go to the end. With a modal, the main verb stays as an infinitive at the end: Sie können … zusagen.

Is zusagen a separable verb? If yes, why isn’t it split here?

Yes, zusagen is separable.

Without a modal: Sie sagen am Telefon zu.
With a modal (infinitive at the end, not split): Sie können am Telefon zusagen.
Perfect: Sie haben am Telefon zugesagt.

Exactly what does zusagen mean here?

Here it means to accept/confirm/RSVP (e.g., accept an invitation or agree to something). Note that zusagen can also mean to appeal to/please: Das Angebot sagt mir zu = “I like the offer.” That second meaning is not intended here.

Do I need an object with zusagen?

Not necessarily. You can:

Use it intransitively: Sie können telefonisch zusagen.
Add a person (dative): Sie können uns am Telefon zusagen.
Add a thing: Sie können die Teilnahme am Telefon zusagen.

What does auch do here, and why is it before am Telefon?

Auch is a focus particle meaning also/too. Placed before am Telefon, it signals “by phone as well (in addition to other options).” Different placements shift focus:

Auch am Telefon können Sie zusagen. (emphasizes the channel)
Sie können am Telefon auch zusagen. (suggests that, on the phone, you can also do the action of confirming, in addition to perhaps asking questions, etc.)

Why am Telefon and not im/auf dem Telefon or per Telefon?

am Telefon (an + dem) = “on the phone,” the normal idiom when you’re speaking by phone.
per Telefon = “by telephone,” a bit more formal/bureaucratic, focusing on the medium.
im/auf dem Telefon would suggest “in/on the physical device,” which is usually wrong here (though auf dem Handy can mean “on the smartphone” when talking about content stored on it).

What case is used in am Telefon, and why?

Dative. am is the contraction of an dem; an takes dative for location (no movement). Telefon is neuter (das Telefon), so dative is dem Telefon.

Is the comma before beispielsweise necessary?

Yes, in standard punctuation this is an explanatory addition (Erläuterung). Such additions introduced by words like beispielsweise/zum Beispiel are set off by a comma: …, beispielsweise noch heute. If it were mid-sentence, you’d set it off with commas on both sides.

What’s the nuance of beispielsweise compared to zum Beispiel or etwa?

beispielsweise = “for example,” slightly more formal/written.
zum Beispiel (z. B.) = very common and neutral in speech and writing.
etwa can mean “for example” in formal writing, but also “approximately,” so context matters.

What does noch add in noch heute? Is it “still”?

Here noch means as early as / even / by the end of today: “for example, even today.” It’s not “still” in the temporal-continuative sense. heute noch is also common and similar. Contrast:

noch heute/heute noch: “as early as today/by today”
schon heute: “already today” (emphasizes earliness)

Is telefonisch a good alternative to am Telefon?

Yes. Sie können auch telefonisch zusagen, beispielsweise noch heute. It’s concise and slightly more formal; very natural in written communications.

How would this look in the informal du form?

Du kannst auch am Telefon zusagen, beispielsweise noch heute.
For plural informal: Ihr könnt auch am Telefon zusagen, beispielsweise noch heute.