“I'm not saying that's true for all Japanese people, of course.”
You're were talking with someone about the differences between Japanese people and people from other countries. You said that Japanese people are usually reserved, but you don't want the listener to think that you believe all Japanese people are like this, so you say this.
I'm not saying that's true for all Japanese people, of course.
Use this phrase to correct something that you think people might misunderstand:
Don't get me wrong — I'm not saying that I disagree with you at all.
This is useful when you think that the listeners might get angry or offended by something that you said.
You often follow "I'm not saying ___" with another sentence that begins with "I'm just saying ___":
I'm not saying that you're wrong. I'm just saying that you probably should have phrased it more politely.
The phrase "of course" is useful to show that you're saying something that's obviously true.
You can put "of course" at the beginning of a sentence or at the end:
Of course, that's not the only way to do it.
We haven't said anything to her about it yet, of course.
Some things that you say are only true if you're talking about a certain group of people or things. To explain which people or things a statement applies to, use the phrase "true for":
A lot of people have trouble losing weight, but that's never been true for me. If anything, I have to work hard to gain any weight.
Research with students has shown that those who don't eat breakfast can't pay attention as well by 10 or 11 a.m., " says Dr. Kenney. "The same is true for adults. We run out of steam."
In the last example above, you can see the phrase "The same is true for adults." "The same is true for ___" is a common way for "true for ___" to appear.