一般现在时的否定句与现在进行时的否定句？

Question

He is doesn't clean the blackboard. 是表示通常不擦黑板，表示他擦过的次数很少？而He isn't cleaning the blackboard. 是说他现在没有在擦黑板，平时都有擦？
以上描述哪里不妥，请指出。

Answer 1

他不擦黑板。
He doesn't clean the blackboard.(一般都不擦黑板)
他很少擦黑板。
He seldom cleans the blackboard.(否定意义的副词，表示“很少”。)
他现在不在擦黑板。
He isn't cleaning the blackboard now.(现在不在擦黑板，不等于平时不擦黑板。)

Answer 2

现在进行时的句子：
肯定句：He's reading an interesting book.
否定句：He isn‘t reading an interesting book.
一般疑问句：Is he reading an interesting book?
肯定回答：Yes， he is.
否定回答：No， he isn't.
OK?