The Tai Chi Classics is a corpus of old texts in classical Chinese ascribed to various past masters, both mythical and historical.
Together they form the original theoretical framework of Taijiquan. Some of the most important texts are of murky origin and diffucult to date. Sometimes the same text is ascribed to different authors. This is what will happen, when manuscripts are copied and passed on in families over generations.
Most of texts are quite short, compressing much information into relatively few characters, and are probably meant to support an oral tradition, which is hard to find anywhere today.
This is why they can be difficult to translate, and different translations will vary, reflecting the individual translator's interpretation of the principles and their general understanding of Taijiquan. Very often, the translations are accompanied by extensive commentary, adding another layer of interpretation on the original text.
But to get as close as
possible to the original meaning of the text, I think it is better to
compare different translations of the actual text and avoid the
commentaries altogether.
About
a handful of the Classics are more prominent than the rest. Below are multiple translations of some of those - without
commentary. The translations have been very slightly edited in order to facilitate comparison.
Zhang San Feng - Treatise on Taijiquan
Explanation of the Thirteen Movements
You can find more translations of the Classics in various places on the internet - for example here, here, and here.
Just be sure to distinguish clearly between the actual Classics and the commentaries
More on the Classics: