以when作宾语从句的句子,主句用什么时态

以when作宾语从句的句子,主句用什么时态

一般疑问句作宾语从句,连接词是whether或if,词义为"是否"在从句中不作任何成份,不可省略.
特殊疑问句：
特殊疑问句作宾语从句,不需另加连接词,疑问句中的疑问代词和疑问副词本身就作连接代词和连接副词.特殊疑问句变宾语从句的公式："连接词（原疑问词）+陈述句语序"
特殊疑问句作宾语从句有以下几种情况：
1.Model:Can you tell me________________________.
1) Who met Liu Fang?
Can you tell me who met Liu Fang
2) Which book is hers
Can you tell me which book is hers
以上两句1）句是疑问词who在句中作主语.句是疑问词which,作主语book的定语,这两个疑问句的语序没发生变化,和陈述句语序相同,换言之,疑问词在句中作主语和主语定语时,本身就是"疑问词+陈述句语序"符合以上公式,直接填入横线作宾语从句：
T：Could you tell me __________________?
T:Who can answer this question
S:Could you tell me who can answer this question?
T:Who lives in this room?
S:Could you tell me who lives in this room
T:Who has the most apples ,Li Lei ,Jim ,or Lily
S:Could you tell me who has the most apples,Li Lei ,Jim ,or Lily
T:Do you know _______________?
T:Which truck has the fewest baskets,the first,the second or the third
S:Do you know which truck has the fewest baskets,the first,the second or the third
T:How many of them lived in the new building?
S:Do you know how many of them lived in the new building
2.特殊疑问句变宾语从句的第二种情况：
Model:Could you tell me_________________?
1)Which book are they talking about?
Could you tell me which book they are talking about
2)When does supper start today
Could you tell me when supper starts today
3)What is he doing now
Could you tell me what he is doing now
从以上三个句子可以看出疑问句在句中作其它成分（即不作主语）或其它成分的定语、状语时,我们应首先把这个疑问句的语序变成陈述句语序,再填上横线作宾语从句,变化公式如下：
把原"疑问词（+所修饰的词）+一般疑问句"改变成
"连接词（原疑问词）+所修饰的词+陈述句"