OXFORD PRACTICE GRAMMAR-147 sau đây là giáo trình lý thuyết tiếng anh và bài tập áp dụng từ cơ bản đến nâng cao , nhằm giúp các bạn có thể tự mình ôn tập và củng cố thêm về nền tảng kiến thức môn Anh văn , tự tin đạt kết quả tốt trong kỳ thi ngoại ngữ | OXFORD PRACTICE GRAMMAR 147 IF WHEN UNLESS AND IN CASE Present simple for the future Look at these examples. You ll be tired tomorrow if you stay up late. Tell me when the water boils. I won t do anything unless you agree. Write the name down in case you forget it. We use the present simple for the future after linking words such as if when unless and in case see also Units 27 and 144B . B If or when If you hear any news can you ring me immediately You might hear some news. I ll probably go for a walk later on if it stays fine. It might stay fine. We use if for something that we think might happen. We use if not when for something impossible or imaginary. If I were you I d refuse. When you hear some news can you ring me immediately You will hear some news. I ll make myself an omelette when I get home tonight. I will get home tonight. We use when for something that we know will happen. We can use either if or when in contexts where they mean every time . If you run you use up energy. When you run you use up energy. C If and unless If. not means the same as unless. can t see if I don t wear glasses. The doctor will be here if she isn t called to an emergency. If you can t pay your bills you ll have to leave. I wouldn t say that if I didn t believe it. I can t see unless I wear glasses. The doctor will be here unless she s called to an emergency. Unless you can pay your bills you ll have to leave. I wouldn t say that unless I believed it. D In case Look at these examples. Take a sandwich with you in case you get hungry. I d better reserve a seat today in case the train is full tomorrow. Laura took two photos in case one of them didn t come out. We use in case to talk about doing something to avoid a possible problem later on. For American English see page 381. Compare if and in case. I ll bring in the washing if it rains. I ll bring it in at the time it starts raining. I ll bring in the washing in case it rains. I ll bring it in now because it might rain later. 147 .
