I dumbed down my English material.

I had used "Advanced Business English" material, but I changed to "Introductory Business English." I dumbed down a notch.

In the Advanced material, although the conversation of each episode was conducted among co-workers and their boss at work, its topics were always away from business itself, and I often felt that the idioms or expressions which were introduced in were not commonly used.
When I browsed the Introductory material, I thought that it was really useful for actual English conversations at work. So I decided to change to it.

The dialogues became a bit easy. It's easy to distinguish words, and there are not so many new idioms and words. On those points, changing the material doesn't seem to be good. However, I can learn many common expressions in business. It has been two weeks since I started using it. I think that it was good decision.