TO UNDERSTAND TAIJIQUAN
The movement style of Taiji is relaxed soft smooth and harmonious.The actions are round and full, while the mind is stable. It requires that you nourish your spirit and energy (shen qi) internally, while externally to use every joint in the body to create spiral silk reeling movement. The result is elegant, natural beauty.
The context for learning Taiji is different now compared to the context in which it originated. People's motivations are no longer always martial, these days you can also practise for health, sport or simply as a leisure activity.
Before it became widely known as Taijiquan, it used to be called soft fist, long fist, thirteen postures and soft hand.
There are a lot of rumours and stories about the origin of Taiji. Most of them come from the Tang dynasty Shi Shuenping, Song dynasty Chang Sanfeng, Ming Dynasty Chang Sanfeng (same pronunciation different words), Ching Dynasty Chen Wangting and Wang Tsungyueh.
Everyone agrees that the the Ming Dynasty CSF, and WTY wrote classic discourses on Taiji. However most Taiji practitioners believe that all Taiji derives from Chen style Taiji. Chenjiagou martial arts originated with Chen Wangting towards the end of the Ming dynasty and the beginning of the Ching (16C-1680) in Wen county, Henan province. Within the Chen family it was passed down from father to son, but not to daughters, so it was difficult for outsiders to see the art and even harder to grasp its essence. This was so until Chen Chang Hsin 1771-1853 taught a man called Hebei Yang Luchan 1799-1872, and it was from this time that Taiji could begin to spread. 
Taiji comes from the boxing of General Chi Chi Guan, combined with Daoyin, breathing exercises, Chinese medical theory while Bagua and five element theory became Taiji's philosophical foundation.
Taijiquan uses peng, lu, ji, an, tzai, li, jou, kao to match the bagua idea of four directions and four corners. It uses forwards backwards, left, right and central equilibrium to match five element theory. Combined these make thirteen postures which are an important practise method.
When you practise Taiji you need to calm your thinking and use your intention to guide your movement, to let your breath and movement combine, so that mind, breath and movement are all in harmony.
The movement needs to be soft, smooth, continuous centred and upright,. The whole thing needs to be harmonised so that it is natural. At the same time the breath needs to be smooth, stable, deep, soft and light.
Taiji movement uses circles in a sophisticated way. The circles are smooth, alive and originate from the waist so that the upper and lower body act as a unified system.
The outside looks soft, but the inside has power. When you use techniques hard and soft support/complement each other. Fajing must concentrate the entire body’s power.
The function of push hands practise to increase and update skill in the application of techniques.
When you practise use stillness to control the opponents movement. Avoid solid and hit empty. Use their power, combine it with your own to send it back on them.
The entire body, mind and hands must be sensitive to gage the strength direction and origin of opponents power, to follow their movement in time and to react appropriately.
Taijiquan has spread to become many systems; In China these are separated into 5 big groups, Chen, Yang, Wu, Wu and Sun. Every school has a unique approach to training but also common content.
Good Taiji fighters have all studied:
- Theory
- Zhan zhuang
- Form exercise (big, middle, small size fast and slow), sometimes stick, saber, sword, spear as well.
- Push hands, single hand vertical, horizontal, diagonal. 2 hand fixed and stepping, Ta lu and zhannien sanshou.
- Single posture practise (basically 13 postures) to be familiar with the smooth use of the technique, timing and power. The body needs to learn to dodge, leap, gallop and wiggle/adjust. This allows to grasp, hold, strike and throw.