Are you using both the Chinese and English versions of AutoCAD? Even Japanese, French, and Italian? In the past, you had to install a Chinese version and an English version respectively. Now, you only need to use a separate Language Pack to switch the language under AutoCAD 2014. In fact, you can use AUTOCAD 2013.
For example, I first installed the Chinese version of AutoCAD 2014. If you take a look at the shortcut, it is actually like this:
"C: \ Program Files \ Autodesk \ AutoCAD 2014 \ acad.exe"/product ACAD/Language "ZH-CN"
However, the English version is required at work, so I open AutoCAD 2014, download the language pack from the help in the upper right corner, download the Language Pack, and install it. After installation, a new English version shortcut is displayed:
"C: \ Program Files \ Autodesk \ AutoCAD 2014 \ acad.exe"/product ACAD/Language "En-us"
With this shortcut, you can start the English version of AutoCAD 2014, instead of installing the English version of AutoCAD 2014!