No, you do not necessarily have to write a long essay to get full marks. The length of an essay is not the sole factor in determining its quality or the marks it receives. What matters most is the content and how well you address the question or topic. It's important to provide a clear and concise argument, supported by relevant evidence and analysis. Focus on the quality of your ideas, the coherence of your writing, and your ability to effectively communicate your thoughts. Length alone does not guarantee high marks; it is the substance and quality of your essay that truly matter.