Learn Hardcore German: Mein Vorgesetzter erklärt mir den Plan im Büro. - My supervisor explains the plan to me in the office.

Grammatically, it is an adjectival noun (a participle or adjective used as a noun). It comes from the adjective/participle vorgesetzt (literally “placed above”), but in mein Vorgesetzter it functions fully as a noun meaning “my superior”.

In German, all nouns must be capitalized, including adjectival nouns like:

der Angestellte – the employee
ein Bekannter – an acquaintance (male)
die Bekannte – an acquaintance (female)
mein Vorgesetzter – my superior (male)

Why is it mein Vorgesetzter and not mein Vorgesetzte?

The form Vorgesetzter here is masculine nominative singular. In this sentence, mein Vorgesetzter is the subject (= “my superior / my boss”), and it refers to a male person.

Patterns for this adjectival noun (with possessive like mein) look like this:

Nominative masculine: mein Vorgesetzter (my male superior – subject)
Nominative feminine: meine Vorgesetzte (my female superior – subject)

So:

Mein Vorgesetzter erklärt mir den Plan. – My (male) boss explains the plan to me.
Meine Vorgesetzte erklärt mir den Plan. – My (female) boss explains the plan to me.

The -er vs -e ending is regular agreement for these adjectival nouns.

Why is it mir and not mich?

German distinguishes between dative and accusative object pronouns:

mich = accusative (direct object: me)
mir = dative (indirect object: to me / for me)

The verb erklären (to explain) uses the structure:

jemandem (dative) etwas (accusative) erklären
= to explain something to someone

So in the sentence:

mir = dative (indirect object: to me)
den Plan = accusative (direct object: the plan)

Therefore mir is correct:
Mein Vorgesetzter erklärt mir den Plan.
= My boss explains the plan to me.

Using mich would be ungrammatical here.

Why is it den Plan and not der Plan?

Plan is a masculine noun:

Nominative: der Plan – the plan
Accusative: den Plan – the plan (as a direct object)

In the sentence, den Plan is the direct object (what is being explained), so it has to be in the accusative case:

Wer? (Who?) – Mein Vorgesetzter (subject, nominative)
Wem? (To whom?) – mir (indirect object, dative)
Was? (What?) – den Plan (direct object, accusative)

So den Plan is the correct accusative form.

What is going on with im Büro? Why not just in dem Büro?

im is a contraction of in dem:

in
- dem → im

We use dem because Büro is neuter (das Büro), and after in with a location (where?) we need the dative case:

Nominative: das Büro
Dative: dem Büro → im Büro

So:

in dem Büro = in the office (correct but formal/explicit)
im Büro = in the office (normal, everyday form)

The sentence uses im Büro because that’s the standard contracted form in spoken and written German.

What case is used with im Büro, and why?

Im Büro uses the dative case:

Büro is neuter: das Büro
Dative singular neuter: dem Büro
in dem Büro → im Büro

With the preposition in, you use:

Dative when it’s about location (where?):
- im Büro – in the office (where is something happening?)
Accusative when it’s about direction / movement (where to?):
- ins Büro (in das Büro) – into the office

In this sentence, it’s describing where the explanation happens (a location), so the dative is used.

Can the word order of the sentence change?

Yes. German word order is flexible, especially for elements like time and place. The finite verb must stay in second position, but many other parts can move for emphasis. For example:

Im Büro erklärt mein Vorgesetzter mir den Plan.
→ Emphasis on where it happens (in the office).
Den Plan erklärt mir mein Vorgesetzter im Büro.
→ Emphasis on what is explained (the plan, not something else).
Mein Vorgesetzter erklärt mir im Büro den Plan.
→ Slight emphasis on im Büro; still natural.

All of these are grammatically correct; the differences are mainly about emphasis and information flow. The original sentence is the most neutral.

Why is the verb erklärt in second position?

German main clauses follow the V2 rule: the conjugated (finite) verb must be in second position in the clause.

In Mein Vorgesetzter erklärt mir den Plan im Büro.

Mein Vorgesetzter = the first element (subject phrase)
erklärt = the finite verb in second position
Everything else follows afterwards.

If you move something else to the beginning, the verb still stays second:

Im Büro erklärt mein Vorgesetzter mir den Plan.
Den Plan erklärt mir mein Vorgesetzter im Büro.

The “second position” is about elements/phrases, not about literal second word.

What tense is erklärt here? Does it mean “is explaining” or “explains”?

Erklärt is 3rd person singular, present tense of erklären.

German present tense can cover several English forms:

Mein Vorgesetzter erklärt mir den Plan. can mean:
- My boss explains the plan to me.
- My boss is explaining the plan to me.

Context decides whether it’s a habitual action or something happening right now. German normally uses the simple present for both of these meanings; the progressive form (is explaining) is usually not expressed with a separate tense.

How does the verb erklären work with objects in German?

The typical pattern is:

jemandem (dative) etwas (accusative) erklären
= to explain something to someone

So in the sentence:

jemandem → mir (to me, dative)
etwas → den Plan (the plan, accusative)

Other examples:

Der Lehrer erklärt den Schülern die Grammatik.
– The teacher explains the grammar to the students.
Kannst du mir das Problem erklären?
– Can you explain the problem to me?

Always remember: erklären takes two objects:
a dative person and an accusative thing.

Could I say Mein Chef erklärt mir den Plan im Büro instead of Mein Vorgesetzter?

Yes, Mein Chef erklärt mir den Plan im Büro is perfectly correct and probably more common in everyday speech.

Nuance:

Chef = boss (informal, everyday, can feel more personal or hierarchical).
Vorgesetzter = superior (more formal, bureaucratic, neutral, commonly used in official or HR contexts).

So both are fine grammatically; Chef is more colloquial, Vorgesetzter is more formal/official.

How would the sentence change if the boss is a woman?

You’d change mein Vorgesetzter (male) to meine Vorgesetzte (female):

Meine Vorgesetzte erklärt mir den Plan im Büro.

Changes:

mein → meine (because the noun is grammatically feminine)
Vorgesetzter → Vorgesetzte (feminine nominative form of the adjectival noun)

Everything else in the sentence stays the same.

Can I say erklärt den Plan mir instead of erklärt mir den Plan?

You can say erklärt den Plan mir, but it sounds marked or unusual in neutral contexts. The normal word order in German is:

Subject
Verb (finite)
Dative pronoun (indirect object)
Accusative noun (direct object)

So the most natural order is:

Mein Vorgesetzter erklärt mir den Plan.

Pronouns, especially dative ones like mir, almost always come before full noun objects like den Plan.

You might hear erklärt den Plan mir in special emphasis (e.g. to contrast with “someone else”), but as a learner, stick to:

… erklärt mir den Plan … – very standard and idiomatic.