A lecture about English
A linguistics professor was lecturing to his English class one day. "In English," he said, "A double negative forms a positive. In some languages, though, such as Russian, a double negative is still a negative. However, there is no language wherein a double positive can form a negative."

A voice from the back of the room piped up, "Yeah, right."

A woman was terribly overweight, so her doctor put her on a diet...
A woman was terribly overweight, so her doctor put her on a diet."I want you to eat regularly for 2 days, then skip a day, and repeat this procedure for 2 weeks. The next time I see you, you'll have lost at least 5 pounds."When the woman returned, she shocked the doctor by losing nearly 20 pounds."Why, that's amazing!" the doctor said, "Did you follow my instructions?" The woman nodded. "I'll tell you though, I thought I was going to drop dead that third day.""From hunger, you mean?""No, from skipping."