回答：1.
系动词be的肯定与否定：be（is, am , are,was, were） +表语（名词、代词、形容词、数词、某些副词、
动名词、分词、
不定式、介词短语、表语从句、疑问词+不定式、表语从句等）；be +not +表语。 例如：
He is a doctor. He is not / isnt a doctor.
I was late yesterday. I was not late yesterday.
His job is tending / to tend the old man.
其他系动词的肯定与否定：助动词、
情态动词+系动词原形+表语；助动词、情态动词+系动词原形+表语。例如：
He does look thin. He does not / doesn't look thin.
The city will become one full of life in five years. The city will not / won't become one full of life in five years.
The room must keep clean. The room need not / keep clean.
2. 助动词、情态动词的肯定与否定：助动词、情态动词+动词原形； 助动词、情态动词+not +动词原形。例如：
We do know it. We do not /don't know it.
They will be back soon. They will not / won't come back soon.
He can swim. He can not / can't swim.