Here is some suggestions from John, and ex-examiner from Australia, about IELTS Speaking vocabulary.
Improving your Vocabulary
- Bands 7 & 8 speakers can use idiomatic phrases quite well. Phrasal verbs (sometimes called 'two-word verbs') are especially good examples of idiomatic phrases. Some examples of these are: 'look after' somebody; 'come up against' difficulties; 'look forward to' something in the future. Even if you believe you are a Band 5 level English speaker, try to increase your knowledge of phrasal verbs.