So you plan to build your vocubulary! Learning vocubulary is a very impoortant part of learning English. If you make a grammar mistake, it may be "wrong" but very often people will understand you anyway. But if you don't know the exact word that you need, it is very frustrating for you, and the person you are talking to. Good business English means having a big vocubulary.
There better and worse ways to build your vocubulary and this book will help to build your vocubulary quickly and effectively