We've run into a few people here whose approach to speaking Chinese is basically to fake it. Which is actually easier than it sounds. The key is really nodding ambiguously when spoken to and muttering the occasional "yes" just to keep things dynamic. For extra points keep your partner unclear whether you're really engaging in conversation with them or simply talking to yourself. And try to avoid buying things until the price comes down on its own.

While the listening exercises on the HSK are pretty effective at weeding out people who don't actually understand Chinese, they're also quite challenging even for even serious students with considerably study time under their belt. In this practice HSK test, listen as we hear the first sentence in a brief conversation. Your challenge is to pick the only sensible response. These listening exercises move at a fast pace and do not repeat. So good luck!