Hyper- and Hypo-
When they start words, for example hypersonic and hyposonic, I just find it really hard to distinguise one word from another in pronouciation.
Any good tips of how to pronouce them clearly and correctly?
Thanks very much.
You're not the only one that has trouble distinguishing them as many native speakers are very lazy and the two come out sounding very similar. However, you simply have to be careful with the "-er" and "-o" sounds.
I would say that it's much more important to pronounce the "hypo-" as distinctly as possible. Most people will have heard lots of words beginning "hyper" and will have no problem, "hypo" is heard less often so needs to be enunciated better. Make the "o" as round as possible - purse your lips, leaving only a small hole in the middle and make it sound like the "o" in "cold".
There is one (unofficial) exception to this. Despite "hypodermic" having the "hypo" at the start, almost no-one pronounces it in the same way that they would "hypoglycaemic" (for example). Most natives will make it sound as if it's spelt "hyperdermic". I'm not defending that pronunciation, it's just the way it is! Perhaps it's because (as far as I know), there's no such thing as a "hyperdermic syringe/needle" ("hypodermic syringe/needle" being the most regularly used phrases containing the word).