Never write a mixed tone IELTS letter!
OK, you are a IELTS General Training student sitting in the writing exam. The invigilator tells you that you can open your test paper and begin. You look at the prompt for the letter. What are you hoping to see? An informal letter, a formal letter, or a semi-formal letter? In my experience, most test-takers would say informal. I mean, writing a letter to a friend is easy, right? WRONG! 🙅♀️ And that’s because 99% of the informal letters that I mark are MIXED TONE.💀