sarah has a headache 中has为什么是过去式

maybe he has a headache=how___ ___a headache maybe he has a headache=he___ ___a headache " she has a headache because she" Jill has a headache the last week. He has a headache 的同义句 - What has a headache the last week. he has a headache 改为同义句 she has a headache.改为一般疑问句 he has a headache的同义句 he has a headache =he has a( ) ( )his head 看答句写问句：No,Sarah has a toothache He has a headache.变成一般疑问句,变成has he a headache可不可以.why?