句子这样改后就可：
I want to confirm that it is free.
I want to make sure it is free.
两者意思相当.高手~~请教下~1、咦~~这个后面为什么不能是疑问句呢？2、I want to make sure it is free or not free?是对的吗？I'am not sure it is free?这句呢？3、I want to make sure that I can cancel the “breakfast”,because I don’t think I really need it.这句是否正确呢？我想把这个问题搞明白，一直很迷糊~~谢谢啦~1. 虽然句子期待对方回答，但不是疑问。2. I want to make sure it is free. （不用加 or not free? 这短句是隐含的。）这句子也不是疑问。如果你要改为疑问，可以这样说：Can you tell me if it is free?3. 这句子建议你这样改：I want to make sure that I can cancel the “breakfast”. I don’t really need it. （不必加because。）上面这些用法是英语为母语的人的习惯用法。不客气。Great!I want to make sure that if"I want to make sure that I can cancel the “breakfast”,because I don’t think I really need it." has canceled "because"and"I" it has become a native sentence.试着用这个句子请教你一下，请指正喔~~~谢谢啦！！！What is a "native sentence"?I want to make sure that I can cancel the breakfast, because I don’t think I really need it. 语法上这句子没有错，但这不是语法的问题。英语有句俗语： language is usage， 它的意思是语言不是仅从语法学的，也是（更重要）从习惯学到的。西方人习惯这样说：I want to make sure that I can cancel the “breakfast”. I don’t really need it.