Let's consider what an examiner might be thinking during part 3 of the speaking test.
Speaking Part 3
After part 2 of the speaking test, the examiner probably has a pretty good idea of the candidate's level. Part 3 is useful because it allows the examiner to probe a little deeper to make sure that he/she is right. For example, if the examiner is unsure about what score to give for grammar, he/she might choose a question that requires the candidate to compare the past with the present (i.e. using different tenses), or a question that requires the candidate to imagine something (perhaps using a conditional).
When I was an examiner, I used part 3 as an opportunity to push candidates a little harder. I tried to get them to open up, express themselves, and explain their opinions. In other words, I was giving them a final chance to impress me with some good English. This is what you should try to do.
Tip: Don't let your energy or effort level drop after part 2. Do your best to leave a good impression on the examiner. This technique will help you.
Note: I'll come back to yesterday's point about 'less common' and 'idiomatic' vocabulary in next Friday's lesson.