Learn Hardcore German: Meine Schwester schreibt einen Fitness‑Blog, und als Bloggerin postet sie fast jeden Tag. - My sister writes a fitness blog, and as a blogger she posts almost every day.

Capital M
Meine is the first word in the sentence, so it’s capitalized for that reason only. Normally, meine (my) is written with a lowercase m.
Ending -e
Meine is a possessive determiner that has to agree with the noun Schwester:
- Schwester is feminine.
- It’s in the nominative case (it’s the subject).
- For feminine nominative singular, the form is meine.

So:

mein Bruder (my brother – masculine nominative)
meine Schwester (my sister – feminine nominative)
mein Kind (my child – neuter nominative)

Why is there no article like die before Schwester? Why not Meine die Schwester?

In German, you normally don’t use a separate article when you already have a possessive word like mein, dein, sein, ihr, etc.

So you say:

meine Schwester (my sister), not meine die Schwester
mein Auto (my car), not mein das Auto

The possessive determiner meine already does the “article job”: it specifies which sister.

Why is the verb schreibt and not schreibe or something else?

The verb is schreiben (to write). It’s conjugated according to the subject meine Schwester:

ich schreibe
du schreibst
er/sie/es schreibt
wir schreiben
ihr schreibt
sie/Sie schreiben

Meine Schwester is sie (she, 3rd person singular), so you use schreibt:

Meine Schwester schreibt … = My sister writes …

Why is it einen Fitness‑Blog and not ein Fitness‑Blog?

Because of gender and case:

Blog is masculine in German: der Blog.
einen is the masculine accusative form of ein.
einen Fitness‑Blog is the direct object of schreibt (What does she write? A blog).

Masculine ein in singular:

Nominative: ein Blog (ein guter Blog)
Accusative: einen Blog (einen guten Blog)

So in this sentence, you need einen Fitness‑Blog (accusative masculine).

What’s going on with Fitness‑Blog? Why the hyphen and capitalization?

Hyphen
German often uses a hyphen between a “describing” noun and the main noun:
- Fitness‑Blog
- Mode‑Blog (fashion blog)
- Reise‑Blog (travel blog)

You could also write Fitnessblog as one word; the hyphen just improves readability.

Capitalization
Both Fitness and Blog are nouns here, and all nouns are capitalized in German:
- Fitness (fitness)
- Blog (blog)

So Fitness‑Blog is correctly capitalized.

How does the comma and und work here? Are these two full sentences?

Yes, you have two independent main clauses joined by und:

Meine Schwester schreibt einen Fitness‑Blog,
und als Bloggerin postet sie fast jeden Tag.

Each has:

a subject (meine Schwester / sie)
a verb in second position (schreibt / postet)

So:

Comma before und is optional in many simple cases in German.
Here it’s used and perfectly fine: it separates the two main clauses clearly.

What does als Bloggerin mean exactly, and why is it als and not wie?

als Bloggerin means “as a blogger / in her role as a blogger.”

als vs wie
- als is used for a role, function, or capacity:
  - Er arbeitet als Lehrer. (He works as a teacher.)
  - Sie spricht als Expertin. (She speaks as an expert.)
- wie is used more for comparison (“like”):
  - Er arbeitet wie ein Verrückter. (He works like a madman.)

So als Bloggerin = in her function as a blogger, not “like a blogger.”

Why no article? With roles/professions after als, German usually drops the article:
- als Bloggerin
- als Lehrer
- als Student
Case and form Bloggerin is feminine (ending -in), matching Schwester. It’s in the nominative because it describes the subject sie (predicate noun).

Why is it Bloggerin and not Blogger?

German often has a masculine and a feminine form for professions and roles:

der Blogger (male blogger or gender‑neutral in some contexts)
die Bloggerin (female blogger)

Since Schwester is clearly female, Bloggerin matches that:

Meine Schwester … als Bloggerin …

Why is sie lowercase? How do I know it doesn’t mean polite Sie?

Sie with a capital S is the formal you.
sie with a lowercase s can mean she or they, depending on context.

Here, context makes it clear:

Earlier: Meine Schwester … (my sister)
Later: … postet sie fast jeden Tag.

So sie refers back to meine Schwester = she.
If it were formal Sie, we would not have meine Schwester as the subject; the whole structure would be different.

Is postet really a German word? How is posten used and conjugated?

Yes, posten is a common borrowed verb in modern German, from English “to post” (online).

It conjugates like a regular -en verb:

ich poste
du postest
er/sie/es postet
wir posten
ihr postet
sie/Sie posten

So with sie (she):

sie postet = she posts

More “classic” German alternatives would be:

sie veröffentlicht Beiträge (she publishes posts)
sie stellt fast jeden Tag etwas online (she puts something online almost every day)

What exactly does fast mean here, and why is it before jeden Tag?

fast means almost or nearly.

sie postet jeden Tag = she posts every day
sie postet fast jeden Tag = she posts almost every day

Position:

fast usually goes directly before the word or phrase it modifies.
Here it modifies jeden Tag, so you get fast jeden Tag.

You wouldn’t normally say sie postet jeden Tag fast, because that sounds like you are modifying postet itself (= “she almost posts every day,” which is odd in German too).

What is jeden Tag grammatically? Why jeden and not jeder?

jeden Tag is an accusative time expression meaning every day.

Tag is masculine: der Tag.
In the accusative singular, the pattern with jeder (every) is:
- Nominative: jeder Tag
- Accusative: jeden Tag

In German it’s very common to use the accusative to express a time span or frequency:

jeden Tag – every day
jede Woche – every week (feminine → jede in nominative and accusative)
jedes Jahr – every year (neuter)

So jeden Tag here says how often she posts.