As an IELTS trainer I probably get asked more questions about idioms than any other single thing. Every day I get questions like: Will using idioms increase my score? Best Online IELTS Coaching in East Delhi. This is one of the most misunderstood areas of the test and making some of the mistakes below can really lower your score rather than improve it. Idioms can be used in the Speaking test and can help you get a higher score because you are using a more informal, natural and conversational type of language, but this does not mean that you should use them in every single sentence.