From a western/English language perspective it can seem that the Tai Chi classics speak in riddles – and that some teachers in the Chinese tradition do not talk much at all about the how and what of Tai Chi movement.
I am coming to think this is a misunderstanding of what is really going on – based on a cultural linguistic gap.
English language as a technology tends to encourage presentation of very tight definitions of specific detailed aspects in isolation. On the other hand perhaps the “fewer words talking in riddles” approach is actually an extremely accurate use of language in a “jargon” sense, where each short description carries within it many layers of a pre-understood body of knowledge – not just of specifics but also of their inter-relationships.
So the injunction to “relax and sink” is hugely accurate and comprehensive at the same time – so long as you share a pre-existing understanding with the speaker in the widest possible terms – which you can then bring to the very focused matter of moving your body, or where you subsequently are able to correlate subconsciously in your practise.
Perhaps like in car racing where fast lap times involve driver skill and car mechanisms – there are needs to train driver awareness, and to develop the suspension and engine components. But in actually driving we speak simply of how to apply steering and the throttle, without all the detail of the vehicle operation in that process.
In this way we find that very little needs to be said – and that which is said is necessarily broad in sweep – simply allowing the subconscious body to operate naturally. It is for us to delve beneath the surface to establish what we need to do to achieve the desired natural outcome. In this we can simply do the exercises and observe the result so that in the process we come to recognise the feelings involved and attach meaning directly to the words. Plus, we can explore intellectually the possibilities, setting up experimental exercises and so on.