哥斯达黎加旅游报价:I asked him 后面是跟if he can 还是if he could?

I asked him 后面是跟if he can 还是if he could? I asked him where did he go last week. 这句话我有个地方不明白！ if (是否) 后面跟什么词 if（如果）后面跟什么词？ 选哪个啊?选项在补充里.If I () you, I () him the truth. If I were you, I would go to look for him.这样倒装对吗? 英文说话该用什么标点符号，如 I asked:"if i can go there?"这样写对吗？ he said he hoped to meet him in the street and was asked if he would like to have a haircut. So he asked him for help but asked him to walk是什么意思