i'm not sure that it is free 肯定句子.
无不确信那个是否免费
你是要改成疑问句吗?
再问： 对 我是想要疑问句。就是想向对方确认某件事情。。。
再答： are you sure that is free ? 你确定那是免费的吗？就完全可以了
再问： I want to make sure that I can cancel the “breakfast”,because I don’t think I really need it.那么这句这样说对不对呢 谢谢啦
再答： i want to make sure that whether i can cancle the “breakfast” or not, because I don’t think I really need it. 或者 i want to make sure that if i can cancle the “breakfast” . because I don’t think I really need it. 加一个"是否" 句子会更流畅谢 whether 表示 “是否” 后面必须加 or not if 表示 “是否” 不用加
再问： 这里加if是必须的吗？如果不加会不会有语法错误呢？whether of not 和if这两句哪个表达更好一些呢？谢啦
