麻烦问下 这地方为什么会出现两个主语 Only if you have a receipt will we change

麻烦问下 这地方为什么会出现两个主语 Only if you have a receipt will we change Only if you want to will you find a way.有语法错误吗?应该分成两个句子?这为什么 If you want to change for a bigger flower,you will have to p There will be only a person in my heart Even if we have no t Only if you want to will you find a way.为什么不是want前置,而是will? If you ____ stop smoking,you will only have a bad cough. "why you will leave?",she said."you have been here only a we If you already have health insurance,the only change （ ） you 麻烦我问下这地方为什么会有两个主语?一句里面允许有两个主语?（there is,for nothing is） if you have a fever,you might have the flu中为什么用might,不用will pray you will have a change of heart if you have a complain to make about the quality,we are will