Ihr Rasierer ist neu, aber heute braucht sie ihn nicht.

In this sentence, Ihr Rasierer most naturally means her razor.

A useful thing to know is that ihr/Ihr can mean different things in German depending on context:

• ihr = her
• ihr = their
• Ihr = your (formal, when talking to one person or more than one person politely)

Because this word is at the beginning of the sentence, it is capitalized anyway, so the capital I does not by itself prove it is the formal your.

The rest of the sentence helps us: aber heute braucht sie ihn nicht = but today she doesn’t need it. That makes her razor the most likely reading.

Because all nouns are capitalized in German.

So:

• der Rasierer = the razor
• die Frau = the woman
• das Haus = the house

This is one of the biggest spelling differences between German and English.

Sie here means she.

German often uses a possessive first and then later repeats the person with a subject pronoun:

• Ihr Rasierer ist neu = Her razor is new
• aber heute braucht sie ihn nicht = but today she doesn’t need it

So the sentence structure is perfectly normal:

• first clause: talking about her razor
• second clause: talking about she

English does the same thing:

• Her razor is new, but today she doesn’t need it.

Because Rasierer is a masculine noun: der Rasierer.

When a masculine noun is replaced by a pronoun in the accusative case, German uses ihn:

• der Rasierer → ihn

So:

• sie braucht den Rasierer nicht
• sie braucht ihn nicht

This is just like saying it in English, except German pronouns reflect grammatical gender.

Ihn is accusative masculine singular.

That is because brauchen usually takes a direct object, and direct objects are in the accusative case.

So:

• sie braucht den Rasierer
• sie braucht ihn

Here:

• sie = subject
• braucht = verb
• ihn = direct object

This is because German main clauses usually put the finite verb in second position.

In the second clause:

• aber = but
• heute = today
• braucht = needs
• sie = she
• ihn = it/him
• nicht = not

Important point: aber is a coordinating conjunction, and it does not count as the first element inside the clause for verb-second word order.

So the real clause begins like this:

• heute = position 1
• braucht = position 2

That is why you get:

• aber heute braucht sie ihn nicht

Here nicht is negating the idea of braucht ihn — in other words, doesn’t need it.

German often places nicht fairly late in the clause, especially when it negates the verb phrase or the whole idea near the end of the sentence.

So:

• sie braucht ihn nicht = she doesn’t need it

If you move nicht, the emphasis can change. In this sentence, the final position is the natural, standard choice.

Yes, that is also possible.

Compare:

• aber heute braucht sie ihn nicht
  = emphasis on today
• aber sie braucht ihn heute nicht
  = a bit more emphasis on she, with today later in the clause

Both are grammatical. The version you were given puts heute early, which highlights the contrast: the razor is new, but today she doesn’t need it.

Because Ihr is a possessive determiner, and it fills the same slot where an article would normally go.

Compare:

• der Rasierer = the razor
• ihr Rasierer = her razor

You normally do not say both together in standard German:

• not ihr der Rasierer

So ihr is functioning like her in English.

Good question. In this sentence, you can tell from the pronoun ihn later on.

Since ihn is masculine accusative, it points back to a masculine noun:

• Rasierer → masculine

If the noun were feminine, you would expect sie as the object pronoun in accusative. If it were neuter, you would expect es.

So the sentence itself gives you a clue about the noun’s gender.

No. Aber does not push the verb to the end.

That is because aber is a coordinating conjunction. It connects two main clauses, and each main clause keeps normal main-clause word order.

So:

• Ihr Rasierer ist neu
• aber heute braucht sie ihn nicht

By contrast, conjunctions like weil and dass introduce subordinate clauses, where the conjugated verb usually goes to the end.

So:

• ..., weil sie ihn heute nicht braucht

That is a different structure.