哦,你说的是if条件句的缩略吧?那就要看从句后面的谓语动词是什么了.
eg.If I were you,I would go to the cinema.
省略后：Were I you,I would go to the cinema.
If I had gone to school,I would have passed the exam.
省略后：Had I gone to school,I would have passed the exam.
注意：省略了的从句中,主句要到装.
祝你成功啊!