He said he would help me with my maths if he --- free. A. was B. will be C. would be D. is 该选什么
问题描述：
He said he would help me with my maths if he --- free. A. was B. will be C. would be D. is 该选什么
答
A.
从句子结构上看：said后面省略了that,动词后有连接词的是宾语从句,而这个从句部分又是个条件状语从句.
条件状语从句中有个原则：if作“如果”的意思时,主句用将来时,从句用一般现在时.简单记就是“主将从现”.
宾语从句有个原则：时态一致,即如果主句用过去的时态,从句里的谓语动词都用过去的时态；如果主句是现在或者将来的时态,从句的时态按语境来定.
故此题选A.
P.S.在虚拟语气中,无论和什么人称连用,be动词的形式都是were.此题并非虚拟语气.