IELTS, being a test of English language proficiency, demands the test-taker to demonstrate a good understanding of Grammar and Vocabulary to be considered a good or expert user of the language. While writing the description for the process diagram essay in the IELTS Academic Writing Task 1, Grammar and vocabulary combined accounts for 50% of the total score. Thus, the test-taker must find out what the common grammar and vocabulary mistakes are and then fix them.