Have you ever dreamed about speaking English in your sleep? Maybe they're good for you.

/ Dreaming makes perfect /
http://www.sciencenewsforkids.org/articles/20100512/Note2.asp
> In the study, 99 college students between the ages of 18 and 30 each spent an hour on a computer, trying to get through a virtual maze.
> They were also told to find a particular picture of a tree and remember where it was.

> For the first 90 minutes of a five-hour break, half of the participants stayed awake and half were told to take a short nap.

] Four of the 50 people who slept said their dreams were connected to the maze.

] When these four people tried the computer maze again, they were able to find the tree faster than before their naps.

> People who had other dreams, or people who didn’t take a nap, didn’t show the same improvement.

I think this study is interesting.
I tend to have some English-language related dreams in my sleep
after I've spent a lot of time to listen English.