weather与if的用法区别

应该是whether和if的用法区别吧?因为这两个都是是否的意思。1。whether ['hweðə] conj。1。是否：to ask whether she will help问她是否能帮帮忙2。不管…还是…：Whether he drives or (whether he) flies,he'll be on time。不管他坐车来还是坐飞机来,他都将准时到达。3。(两者中的)任何一个：taxation to support the war,whether just or not支持正义或非正义战争的赋税pron。[古语](两者中的)哪一个；(两者中的)任何一个adj。[古语](两者中的)哪一个；(两者中的)任何一个2。ifif [if] conj。1。[表示条件或假设]如果；假如,倘若,要是：If I knew,I would say。如果我知道,我就说了。If I were you,I would have failed。如果我是你,我可能会失败的。2。尽管；虽然；即使：If he is little,he is strong。他尽管年纪小,力气倒蛮大的。If I am wrong,you are not right。即使我错了,你也不对。3。是否：I don't know if he is at home。问他是否在家。Ask him if he's at home。我不知道他是否在家。4。当…时,就：If I do not understand,I ask questions。当我不懂时我就问。If I feel any doubt,I ask。我有疑问时就问。5。[表示愿望、感叹]要是…多好：If I hadn't lost my purse!我的钱包要是没丢多好!6。[与 will,could 等连用,表示婉言请求]：If you will keep waiting for a while,they'll soon be back。请你再等一会儿,他们很快就会回来了。7。[与动词否定式连用,表示惊讶、愤怒等]：If isn't Stephen!那不是史蒂芬吗!n。1。疑问；设想；有疑问的事2。条件,必需的条件；规定