Learn Hardcore German: Für dich ist das Zweitbeste heute, dass du früh nach Hause gehen kannst. - For you, the second best thing today is that you can go home early.

Neutral/basic order would be: Das Zweitbeste heute ist für dich, dass …
By putting Für dich first, the speaker emphasizes “for you” – i.e. from your point of view or as far as you’re concerned.

Grammatically, Für dich is just a prepositional phrase; it is moved to the front (a process called Vorfeldbesetzung / topicalization) for emphasis, but the verb ist still remains in second position:

1st position: Für dich
2nd position (finite verb): ist
rest of the sentence: das Zweitbeste heute, dass …

What case is dich and why is that form used with für?

Dich is the accusative singular of du (you, singular informal).

The preposition für always takes the accusative case:

für mich (for me)
für dich (for you)
für ihn (for him)
für sie (for her / for them), etc.

So für dich is required by the preposition; you cannot say für du.

Why is it das Zweitbeste and not something like die Zweitbeste or der Zweitbeste?

Zweitbeste here is a nominalized adjective – an adjective being used as a noun, meaning roughly “the second-best (thing)”.

When you talk about an abstract or unspecified “thing” in German, you often use the neuter article “das”:
- das Gute (the good [thing])
- das Beste (the best [thing])
- das Schlimmste (the worst [thing])
- das Zweitbeste (the second-best [thing])

So das is not agreeing with some explicit noun; it’s the normal neuter “thing” usage for this kind of expression. Der Zweitbeste could mean the second-best man/male, die Zweitbeste the second-best woman/female; das Zweitbeste is neutral and abstract.

Why is Zweitbeste capitalized? Shouldn’t adjectives normally be lowercase in German?

You’re right that adjectives are usually lowercase, but they are capitalized when they are turned into nouns (nominalized).

In this sentence:

As an adjective: das zweitbeste Angebot (the second-best offer) – lowercase
As a noun on its own: das Zweitbeste (the second-best [thing]) – capitalized

Because Zweitbeste is standing alone and functioning grammatically as a noun, it is written with a capital letter.

What is the role of heute, and where can it appear in the sentence?

Heute is an adverb meaning “today”.

In the given sentence, it narrows the situation to today:

Für dich ist das Zweitbeste heute, dass …
→ Among the good things today, the second-best one for you is that …

You can move heute to other positions without changing the core meaning:

Für dich ist heute das Zweitbeste, dass du früh nach Hause gehen kannst.
(slight emphasis on today as the time frame)
Heute ist für dich das Zweitbeste, dass du früh nach Hause gehen kannst.
(stronger focus on today at the very start)

All are grammatically correct; the differences are mostly in emphasis and rhythm.

Why is there a comma before dass, and what kind of clause follows it?

In German, dass introduces a subordinate clause (Nebensatz), and subordinate clauses must be separated from the main clause with a comma.

Main clause: Für dich ist das Zweitbeste heute,
Subordinate clause: dass du früh nach Hause gehen kannst.

The dass-clause here functions as a content clause / complement clause. It tells us what the “second-best thing” is:

The second-best (thing) is that you can go home early.

So the comma is mandatory because we’re going from an independent main clause to a dependent subordinate clause introduced by dass.

Why is the word order dass du früh nach Hause gehen kannst, with kannst at the end?

In German subordinate clauses (like the one introduced by dass), the finite verb goes to the end of the clause.

Structure here:

dass (subordinator)
du (subject)
früh (adverb of time)
nach Hause (direction/place)
gehen (infinitive)
kannst (finite verb, modal) → last

So: dass du früh nach Hause gehen kannst.

This verb-final rule is a central feature of German grammar in subordinate clauses.

Why is it gehen kannst and not kannst gehen at the end?

In clauses with a modal verb + infinitive in German:

In main clauses, the finite verb is 2nd and the infinitive goes to the end:
- Du kannst früh nach Hause gehen.
In subordinate clauses, the whole verb complex moves to the end, and the finite modal normally comes last:
- …, dass du früh nach Hause gehen kannst.

So the standard order in a dass-clause is:

… Infinitive + finite modal (… gehen kannst)

You will sometimes hear other orders in colloquial speech, but “… gehen kannst” is the standard, textbook-correct version.

Why is it nach Hause and not zu Hause?

German distinguishes direction vs. location:

nach Hause = to home, home(ward) → movement towards home
- Ich gehe nach Hause. (I’m going home.)
zu Hause = at home → location at home
- Ich bin zu Hause. (I’m at home.)

In the sentence you gave, the idea is going home, i.e. a movement, so nach Hause is correct:

… dass du früh nach Hause gehen kannst.
→ that you can go home early.

Why is früh placed before nach Hause, and could the order be different?

Früh is an adverb of time (“early”) and nach Hause indicates direction/place.

German has a common order rule for adverbials: time – manner – place (often remembered as TMP). Here we’re dealing with time and place/direction:

früh (time)
nach Hause (place/direction)

So früh nach Hause follows the natural order:

… dass du früh nach Hause gehen kannst.

You could move früh to other positions for emphasis (for example dass du nach Hause früh gehen kannst) but that would sound unusual or awkward in standard German; früh nach Hause is the normal, idiomatic order.