Many non-native English speakers make the mistake of thinking that formal language is always a safe language choice. This is not the case. These days, the American workplace style is becoming more casual and language is going the same way. Even TED talks include casual, even slightly crass language.
The point of very casual, slightly crass words, like crap or bad-ass, is that they are punchy. They are memorable. They stick out. Don't do this with most clients. But, if you use such a style with colleagues or in a speaking test like the G.B.C., it is a winning strategy.
Many of you have already heard a lot of advice on this, things like look the person in the eye, think of interesting topics to discuss in advance, look, nod and smile to show that you're paying attention, repeat back what you just heard or summarize it. So I want you to forget all of that. It is crap.
We can still be optimistic in the long term, and we can still be ambitious about what we fight for and what we expect from our governments, from our planet. Corals have been living on planet Earth for hundreds of millions of years. They survived the extinction of the dinosaurs. They're bad-asses.
Use casual, punchy words to drive home your point. Don't just say something is bad—say, "It's crap." Don't just say it's good—say, "It's awesome." If you can use this strategy correctly, you'll seem like a total bad-ass.
crap [noun, casual]—something bad or terrible.
bad-ass [noun, casual]—a powerful, tough, cool person (or, in this case, animal).