Do I need advanced vocabulary to score Band 7 in IELTS Speaking?
You do not need to fill your answers with unusual or memorised “high-level” words. Examiners are interested in whether you can choose vocabulary that communicates meaning naturally, accurately and with enough flexibility for different topics.
Work on replacing vague or repeated words with more precise everyday language. For example, instead of describing every change as “big”, consider whether “significant”, “rapid” or “substantial” fits the context. Learn common collocations and practise using new words in complete spoken answers. Incorrect or forced vocabulary can make a response weaker, not stronger.