- OK.If my grandma___free tomorrow,she will teach us.( ) A. is B. are C. am D. will be答案根据题干可知,本句是if引导的条件状语从句,遵循"主将从现"原则,即主句用一般将来时,从句用一般现在时表将来;be free"空闲的",固定词组;从句的主语my grandma是第三人称单数形式,...