Der Einspruch ist schriftlich.

Usually, yes. Einspruch often means objection, especially in a formal, legal, or administrative context.

Depending on the situation, it can refer to:

• an objection
• a formal protest
• in some contexts, a kind of appeal against a decision

So this is not the everyday word you would usually use for casually disagreeing with someone in conversation. It sounds more official.

Einspruch is a masculine noun, so its nominative singular article is der.

In this sentence, der Einspruch is the subject, so it appears in the nominative:

• der Einspruch = the objection

Unfortunately, grammatical gender usually has to be learned together with the noun:

• der Einspruch

That is why German learners are usually encouraged to memorize nouns with their articles.

It is in the nominative case because it is the subject of the sentence.

The structure is:

• Der Einspruch = subject
• ist = verb
• schriftlich = predicate adjective / description

So the sentence follows the basic pattern:

• The objection is written/in writing

This is normal German main-clause word order:

• Subject + verb + complement

German main clauses usually put the finite verb in the second position. Here:

1. Der Einspruch
2. ist

Then comes the description:

• schriftlich

So the sentence is completely standard in structure.

Because schriftlich comes after the verb ist and is being used predicatively.

In German, adjectives behave differently depending on where they appear:

• attributive: before a noun, with an ending
  
  • der schriftliche Einspruch
• predicative: after sein, werden, bleiben, with no ending
  
  • Der Einspruch ist schriftlich.

So here, schriftlich does not take an adjective ending.

It is best understood as an adjective used predicatively.

It describes the noun Einspruch through the verb sein:

• Der Einspruch ist schriftlich.

This is similar to:

• Das Haus ist groß.
• Das Wetter ist gut.

In all of these, the final word is an adjective used after sein.

Literally, schriftlich relates to writing, so written is close. But in many contexts, especially official ones, it more naturally means:

• in writing
• submitted in written form
• written rather than verbal

So in an administrative or legal context, Der Einspruch ist schriftlich often suggests that the objection is in written form.

English does not always translate this naturally word-for-word, so written is possible, but in writing is often better.

Yes, it sounds formal and somewhat official or legal.

Both words contribute to that:

• Einspruch is often used in formal/legal settings
• schriftlich is common in instructions, rules, and official language

This is not the kind of sentence you would usually hear in casual everyday conversation unless the topic itself is formal.

Yes, but it sounds a bit terse or context-dependent on its own.

A fuller version might be:

• Der Einspruch muss schriftlich erfolgen.
• Der Einspruch muss schriftlich eingereicht werden.

Those mean something like:

• The objection must be made in writing.
• The objection must be submitted in writing.

So Der Einspruch ist schriftlich is grammatically fine, but in real-life official German, a longer phrasing is often more natural if you want to express a rule or requirement clearly.

Yes, if you mean an objection rather than the objection.

Compare:

• Der Einspruch ist schriftlich. = The objection is in writing.
• Ein Einspruch ist schriftlich. = An objection is in writing.

But in actual usage, the definite article often sounds more natural when referring to a specific objection already known from the context.

Then schriftlich would become an attributive adjective, so it would need an ending:

• der schriftliche Einspruch

For example:

• Der schriftliche Einspruch liegt vor.
  = The written objection is available / has been submitted.

So compare:

• Der Einspruch ist schriftlich.
  Here schriftlich describes the objection after the verb.

• Der schriftliche Einspruch
  Here schriftliche comes before the noun and must take an adjective ending.