The click sounds I mentioned yesterday are only found in a small number of languages spoken in southern Africa. Somewhat similar sounds, known as interjections, are used in others languages, though not as in the role of consonants. Instead they convey various extra information about the speaker’s mood or opinion.
For example, in English you might tut or tsk when you’re irritated by something. Whistles can be used to indicate appreciation or surprise, among other things, and the sucking of air through the teeth is often a sign that more money than was originally expected is likely to change hands, especially when employed by a car mechanic or a builder. Ah ha! can be used to show that you’ve understood something; huh!? for incomprehension; ow! when you hurt yourself; oh! for surprise; um when you’re not sure what to say; and oh for disappointment, as in “oh well, never mind (put the kettle on/have a nice cup of tea)” – very British expression that one!
What interjections in your language, and how are they used?