一般陈述句：I am a worker.I work as a worker.
改为否定句:I am not a worker.I doesn't work as a worker.
改为疑问句：Are you a worker?Do you work as a worker?
Yes,I am.Yes,I do.
No,I am not.No,I don't.
根据括号部分提问：
（I ）am a worker.（ I ）work as a worker.
问：Who is a worker?Who work as a worker?
I am a (worker).I work as a (worker).
问：What are you?Who works as a worker?
其中,where表示地点,how 表示怎么样,which表示选择.
一般情况下,be动词后+not变成否定句,动词变否定在动词前加doesn't/don't/didn't,可根据动词的形式决定.情态动词后加not变否定句.
改一般疑问句时,一般只要主谓交换位置,be动词和情态动词都属于这种情况.而含有动词的句子变一般疑问句时,则要用do/does/did放于句首,主谓位置不变,但是动词必须还原.