1) ''He is not that good a person!'' A better option is "He is not that good of a person!" Like your example, this is used in response to someone's suggestion that the "he" in question might do something good. You disagree and declare that "he" is not that good of a person. 2) ''She is not a person that good!'' This construction is awkward, and while a native English speaker may understand what you are trying to say, it will require some effort on their part as it is not the construction normally used to express the idea you are trying to convey.

toddler's talk 1

I have 2-year-old twins. They recently entered the so-called "terrible-twos", especially my daughter.

She cried out loud twice yesterday because of stubborn ideas and wanted do something all by herself. In the morning, when we got her dressed, she wanted to get dressed all by herself. And she kept crying and yelling, "Dress by myself! Dress by myself!" repeatedly. (『自己穿！自己穿！』in Chinese, I want to know the correct way to express this meaning in a two-year-old kid tones. PLEASE correct me in simple and short form of common native speaker kid's use. THANKS!)

Again, in the same evening, she cried lots of tears just because we turned off the light for bedtime. We had to turn on the light immediately. Little did we think, she yelled, "On by myself! On by myself!" (『自己开！自己开！』in Chinese, again, any proper word as a two-year-old tone?) We had no choice but to turn on the light again and let her turn it off by herself.

My wife and I love our kids deeply, and just hope the tantrums will be gone soon.