Appropriateness and Style ("Angemessenheit") on the essay

"Appropriateness" here refers mainly to the style and register you use in your essay.  

Academic style

1. Your essay must be broadly in academic style. This is partly about your relationship to the reader, which needs to be slightly distanced, and assume that the reader is intelligent and does not need shouting at. Moroever, your essy should be addressed to the public at large, and not to the person you expect to be grading it.  You can bring your own personal experience into the essay, but avoid personal commentary about the exam itself. 
2. Use only complete sentences. In particular:

1. • Sentences need a verb and a main clause
   • Avoid sentences beginning with And.../But.../So...
   • Only start with "Because..." if you have a second half of the sentence,
     e.g. Because America is the most powerful nation, it has a responsibility to maintain peace."
     ...is a complete sentence.
     "Because America is the most powerful nation." is not a complete sentence.
   • Make sure your sentence has a verb and a main clause (Hauptsatz)
     Avoid overuse of "you", "I" and other personalised forms ("I think", "We should", "You cannot"). You can often avoid "you" by using a Passive. For example, the last sentence could become, "Use of "you" can often be avoided by using the Passive."
     English academic style uses many Passive forms e.g. "it can be seen that", or neutral forms such as "is preferable". The occasional use of "In my view,…", "I would argue that…" is acceptable.

Appropriateness in the way you start

Very often the essay task will be in the form of a question such as "Do you think that …" or "In your opinion should…"  Please do not answer these questions directly!  (e.g. do not say "I agree with this question"). It is a convention of academic writing to introduce the readers to the topic as if they do not have the title in front of them.

Thus, the following are examples of what is not appropriate:

"This is a difficult question"

" I don't think I know how you want me to answer this question…"

"In the short time I have to write this answer…"

Writing something like the above examples will result in a lower grade.

Further points to remember in your composition:

Vary the length of sentences. 

Avoid the use of slang or informal language.

Avoid the use of contractions (for example, "he'd", "it's")

Avoid using abbreviations.

Certain abbreviations, which indicate organizations (such as NAFTA or the UN) are acceptable, but avoid using grammatical abbreviations (such as etc, or e.g.).

Avoid using foreign (non-English) words.

-->If you need to talk about something unique to Germany or some other country (such as Abitur) use an English equivalent and give the original in brackets the first time you mention it.

Avoid over use of rhetorical questions.

Do not generally use exclamations (sentences which end with, or feel as though they want to end with a "!").

Finally, avoid banal and boring statements of the type "there are many advantages and disadvantages to this question/problem/solution." or "This is a very difficult question".