When I learned Japanese I found I could spit out a lot of words without actually saying anything of substance. "sou sou! sou desu ka... eeto des ne... "
We had an exercise once in Japanese class for who could go longest on hesitation noises without including substantial content. I remember losing at only 46 seconds. This is not a Japanese exercise, this is a fluency exercise. All languages have a right way to say nothing because nothing is often the right thing to say.
P.S. There are very fluent and fluid ways to say absolutely nothing of substance in both English and Japanese. Try playing the improv game "Talk like a politician": given an accusation of a true statement ("You had a banana for lunch"), dispute the charge without actually saying that you did not have a banana for lunch. You can use arbitrarily sophisticated English (or Japanese) for this.