Meine Schwester hat heute frei.

Because Schwester is a feminine noun in German: die Schwester.

The possessive word mein changes its ending depending on:

• the gender of the noun
• the case
• whether the noun is singular or plural

Here, Schwester is:

• feminine
• singular
• in the nominative case, because it is the subject of the sentence

So the correct form is meine Schwester.

A few comparisons:

• mein Bruder = my brother
• meine Schwester = my sister
• mein Kind = my child
• meine Eltern = my parents

It is in the nominative case.

In Meine Schwester hat heute frei, meine Schwester is the subject, meaning it is the person doing or experiencing the action/state.

You can find the subject by asking: Who has today off?
Answer: Meine Schwester.

That makes it nominative.

Because all nouns are capitalized in German.

So:

• Schwester is capitalized because it is a noun
• heute is not capitalized because it is not a noun
• frei is not capitalized because it is not a noun here

This is one of the most noticeable spelling rules in German.

frei haben is a very common German expression meaning to have time off, to be off work/school, or not to have to work/study that day.

So Meine Schwester hat heute frei literally looks a bit like My sister has free today, but that is not how natural English works. Idiomatically, it means:

• My sister has the day off today
• My sister is off today

In this sentence:

• hat = third person singular of haben
• frei = part of the expression frei haben

So you should learn frei haben as a set phrase.

Yes, frei is an adjective, but it is being used predicatively, not directly before a noun.

Compare:

• ein freier Tag = a free day

  • here freier comes before the noun, so it takes an ending

• Meine Schwester hat heute frei

  • here frei comes later in the sentence and does not take an ending

This is very common in German. Predicative adjectives usually stay in their basic form:

• Das ist gut.
• Er ist müde.
• Sie hat heute frei.

Because German main clauses normally follow the verb-second rule.

In a standard statement, the conjugated verb comes in the second position:

• Meine Schwester | hat | heute frei

The first position is taken by the subject here, so the verb comes right after it.

You can also move another element to the first position, but the verb still stays second:

• Heute hat meine Schwester frei.

That is also correct.

Yes, absolutely.

Both are correct:

• Meine Schwester hat heute frei.
• Heute hat meine Schwester frei.

The difference is mainly emphasis:

• Meine Schwester hat heute frei starts with my sister
• Heute hat meine Schwester frei emphasizes today

This is very common in German: you can move parts of the sentence to the front for focus, but the conjugated verb still stays in second position.

Because heute is a time expression, and German often places time words before the final predicate element like frei.

So:

• Meine Schwester hat heute frei sounds natural
• Meine Schwester hat frei heute is much less natural in standard German

A useful pattern is:

• subject + verb + time expression + other information

For example:

• Ich arbeite morgen nicht.
• Wir haben am Freitag frei.
• Sie kommt heute spät.

Sometimes, but the meaning is not exactly the same.

Meine Schwester hat heute frei specifically means:

• she has time off
• she does not have to work or go to school today

Meine Schwester ist heute frei more often means:

• she is free/available today
• she has no plans
• she is not busy

So if you mean she has the day off, hat frei is the clearest and most idiomatic choice.

The most direct negation is:

Meine Schwester hat heute nicht frei.

This means:

• My sister does not have the day off today
• My sister isn’t off today

Here, nicht usually comes before frei, because it is negating that idea.

You could also say something more explicit depending on context:

• Meine Schwester muss heute arbeiten. = My sister has to work today.
• Meine Schwester hat heute keinen freien Tag. = My sister doesn’t have a day off today.

In a yes/no question, German usually puts the conjugated verb first:

Hat meine Schwester heute frei?

That means:

• Does my sister have the day off today?
• Is my sister off today?

This is the normal pattern:

• statement: Meine Schwester hat heute frei.
• question: Hat meine Schwester heute frei?

The base form is haben, which means to have.

hat is the third person singular form:

• ich habe
• du hast
• er/sie/es hat
• wir haben
• ihr habt
• sie/Sie haben

Since meine Schwester is equivalent to sie in the singular sense of she, the correct verb form is hat.

Not always. frei can mean several related things depending on context, such as:

• free = not occupied / available

  • Ich bin morgen frei.

• off = not working / not in school

  • Ich habe morgen frei.

• open / unblocked / clear in some contexts

  • Der Platz ist frei. = The seat/space is free.
  • Die Straße ist frei. = The road is clear.

So in this sentence, frei does not simply mean free in the broad English sense. It is part of the expression frei haben, which specifically means to have time off.

Yes. frei haben is flexible and can refer to being off from:

• work
• school
• classes
• regular duties

So Meine Schwester hat heute frei could mean:

• she doesn’t have to work today
• she doesn’t have school today
• she has a day off from her normal schedule

The exact meaning depends on context.