Yes you can - if you have the right book!
This book is for complete beginners who, for some reason, cannot take classes. It is also helpful for ballet students who want to improve their technique, as well as for students of other forms of dance or even sport. For parents whose children are studying ballet, it can be of great help.
In short, this book is for everybody interested in ballet technique - of all ages and fitness levels.
The basic posture, all barre exercises, and some center work are presented here with accurate descriptions and illustrations. Even the most common errors are described in detail.
Professional dancers need personal guidance. But everybody else can very well acquire a basic understanding of ballet studying at home. Even if you attend ballet classes, a very big portion of what you learn there, is in fact based on verbal instructions. You cannot learn ballet only by watching (for ex videos). But you can learn ballet by listening to instructions or reading them, and combining this with the study of illustrations and videos.
More info: http://helisusa.info/english