Learn Hardcore German: Heute bleibe ich zu Hause, statt mit meinen Freunden in die Bar zu gehen. - Today I’m staying at home instead of going to the bar with my friends.

German main clauses normally have the finite verb in second position (the V2 rule). You can put different elements in the first position to emphasize them:

Heute bleibe ich zu Hause. – Emphasis on today (today, as opposed to other days).
Ich bleibe heute zu Hause. – More neutral; the emphasis is more on I stay at home.

Both mean the same in normal conversation, but Heute bleibe ich… slightly highlights today as the special circumstance.

Why is it mit meinen Freunden and not mit meine Freunde?

Because mit always takes the dative case, and you also need the plural form.

Preposition: mit → always dative
Possessive determiner: mein in dative plural = meinen
Noun: Freund in plural dative = Freunden (plural dative nouns usually get an extra -n)

So:

Nominative plural: meine Freunde
Dative plural: mit meinen Freunden

mit meine Freunde is wrong because:

meine is not dative plural
Freunde has no dative plural -n

Why is it in die Bar and not in der Bar?

Because in is a two-way preposition (Wechselpräposition) and the case depends on the meaning:

Accusative (Wohin?) = movement into something
→ in die Bar = into the bar (direction)
Dative (Wo?) = location in something
→ in der Bar = in the bar (location)

In your sentence, you are going to the bar, so it’s in die Bar (accusative, feminine singular: die Bar → in die Bar).

Why zu Hause here and not nach Hause?

zu Hause and nach Hause have different functions:

zu Hause = at home (location, “where?” – dative)
- Ich bin zu Hause. – I am at home.
- Ich bleibe zu Hause. – I’m staying at home.
nach Hause = (to) home (direction, “where to?” – like accusative)
- Ich gehe nach Hause. – I’m going home.

In your sentence, the idea is “I stay at home” (location, not movement), so zu Hause is correct, not nach Hause.

Why is it zu Hause with a capital H, and why Hause and not Haus?

Two points:

Capital H
Hause comes from the noun das Haus. In German, nouns are capitalized, and in this fixed expression, Hause still behaves like a noun, so it keeps the capital H.
Hause vs. Haus
zu Hause / nach Hause use an old dative form Hause (with the extra -e). This -e ending is mostly outdated in modern German but survives in a few set phrases:
- zu Hause
- nach Hause
- im Hause Schmidt (very formal/old-fashioned)

You can’t replace zu Hause with zu Haus in standard written German; zu Hause is the correct fixed expression.

What exactly does statt do here, and why do we say statt … zu gehen?

Here, statt means instead of and introduces an infinitive clause:

statt mit meinen Freunden in die Bar zu gehen
= instead of going to the bar with my friends

Structure:

statt
- (something in infinitive form with zu)
The full clause is: statt (dass ich) mit meinen Freunden in die Bar gehe
In German, we shorten that to the infinitive construction:
- statt mit meinen Freunden in die Bar zu gehen

So:

statt = instead of
zu gehen = to go (infinitive with zu at the end of the clause)

Why is there a comma before statt?

Because statt mit meinen Freunden in die Bar zu gehen is an infinitive clause, and in standard written German, such clauses are normally separated by a comma when they are longer or have their own “marker” word like statt, um, ohne, etc.

Pattern:

Hauptsatz, statt … zu + infinitive

So:

Heute bleibe ich zu Hause, statt mit meinen Freunden in die Bar zu gehen.

The comma clearly shows the boundary between the main clause and the infinitive clause.

Why is the verb gehen all the way at the end of the phrase statt mit meinen Freunden in die Bar zu gehen?

In German infinitive clauses with zu, the infinitive verb goes at the end of the clause:

… zu gehen
… es zu machen
… Deutsch zu lernen

So the structure is:

statt
- [various elements] + zu
  - infinitive (at the very end)

In your sentence, the various elements are:

mit meinen Freunden
in die Bar

That gives:

statt mit meinen Freunden in die Bar zu gehen

You can’t move gehen earlier; German grammar requires it at the end here.

Are the two zu in zu Hause and zu gehen the same kind of word?

They are the same form zu, but they have different functions:

zu in zu Hause
- a preposition meaning roughly at (here in the sense “at home”)
- fixed expression: zu Hause = at home
zu in zu gehen
- an infinitive marker, like English to in to go, to eat, etc.
- used in infinitive clauses: zu gehen, zu essen, zu bleiben

So, same spelling, but:

in zu Hause → preposition
in zu gehen → part of the verb construction (infinitive marker)

What gender is Bar, and why is it in die Bar?

Bar in German is feminine:

Nominative singular: die Bar
Accusative singular: also die Bar

With the preposition in expressing movement (Wohin?), we need accusative:

in die Bar = into the bar

So:

Feminine noun → die Bar
Accusative singular after in (motion) → still die Bar
Combined: in die Bar

Does Freunde mean only male friends, or can it include female friends too?

Freunde is the masculine plural, but in standard usage it is also the generic form for a mixed group:

Only male friends: meine Freunde
Only female friends: meine Freundinnen
Mixed group (male + female): usually also meine Freunde

So in your sentence, mit meinen Freunden can naturally mean:

a group of male friends, or
a mixed group of friends

If you want to be explicit about only women, you’d say mit meinen Freundinnen.

Could I replace statt with anstatt? Is there any difference?

Yes, you can also say:

… zu Hause, anstatt mit meinen Freunden in die Bar zu gehen.

statt and anstatt are both correct here and mean the same (instead of). In modern German:

statt is more common, a bit shorter and more neutral.
anstatt can sound slightly more formal or written, but it’s not wrong.

In your sentence, statt is perfectly natural and typical.

Is there another way to say this, like using lieber … als …? Would the meaning change?

Yes, you could say, for example:

Heute bleibe ich lieber zu Hause, als mit meinen Freunden in die Bar zu gehen.

Comparison:

statt … zu gehen = instead of going …
lieber … als … = rather … than …

The meaning is very close:

statt focuses on the substitution: doing A instead of B.
lieber … als … adds a nuance of preference: you’d rather do A than B.

Both versions make perfect sense in this context.