This question comes from Martin in Texas.
Martin, nothing is wrong with you. It can take years of doing the form to get deep into the postures. This applies to all aspects of Tai Chi: appropriate leg stances, arm and body position, as well as proper breathing, and meditation, or emptiness of mind. The way water erodes limestone was the way Professor Cheng would describe the process of perfecting your form. As I have said in other forums, you may see changes from week to week, or month to month, if you are a good beginner and bring natural talent or experience of other arts to your practice. But even if you are not so talented or experienced, you will see changes and improvement with the years of your practice of Tai Chi.
And this is not something to worry about. Tai Chi is an art where one strives for self-perfection. Your Tai Chi at one year will look different from your Tai Chi at 5 years, and 10 and 20 and 25 and so on. At 40 years, I have climbed the foothills of Tai Chi, but not the mountains. I have something to offer those of you who are behind me on this path. But I am not yet at its end. And happily so. If I am stuck where my mind cannot see the next horizon, I am afraid I will stagnate. I improve gradually, as you do, and lead you along the path I have trod.
To come back to where you are, the postures are moving yoga and it can take a while to develop the flexibility to get there. However, just practicing them is helpful, as far as you can get into the postures. Over time you will get there. As a beginner and as an intermediate (or as a person with an injury), just do them as far as is comfortable. Please remember comfortable, you can only injure yourself if you push through being comfortable. That is the one commandment of Tai Chi. The Chi will flow when you are comfortable and can do the postures properly, and if one thing needs to be foregone, between correct posture and comfort, it is the correct posture because you can injure yourself if you go beyond that comfort zone. Then it is not Tai Chi, but injury that you will promote. If you can be patient, the proper posture will come to you with ease, in time. You will get there over the years of your practice. And keep in mind, being comfortable in the practice of Tai Chi is very important. The Chi flows best when you are relaxed, and comfortable.
In T’ai Chi,