什么时候用do和are用来做一般疑问句开头

当陈述句中有am和are的时候需要把他们提前,其中am要变成are.
I am Linda--Are you linda?
they are students--Are they students?
当陈述句中谓语是动词原形的时候,借助动词do 并提前.如果是单三式,就借助动词does并提前
he likes apples.--does he like apples?
they like apples--Do they like apples?