Unit 3 Festivals and Customs Grammar and usage 虚拟语气课件-2024-2025学年高中英语译林版（2020）必修第二册

Unreal Conditionals 非真实条件虚拟语气 If you enjoy scuba diving or snorkeling, the Caribbean and the South Pacific Seas are wonderful places to visit. If you visit these places, you will find beautiful coral reefs full of a variety of ocean life. Coral is a living creature that can be hard or soft. Coral reefs are formed by small creatures called coral polyps. When the coral polyps take calcium from seawater, they can turn the calcium into limestone shelters. A coral reef is formed if several colonies of coral polyps work together to create a large home. Title If you enjoy scuba diving or snorkeling, these are wonderful places to visit. Real conditions talk about real situations, such as facts and regularly occurring events. If you visit, you will find beautiful coral reefs full of a variety of ocean life. Real in the present Real in the future If there were no coral reefs, several species would not exist. Even though coral reefs cover less than one percent of the earth’s surface, they provide a home to about 25% of all marine life. Without the protection and cover of coral reefs, animals like oysters, clams, grouper and snapper would die. These animals are important sources of food for other animals. If the reefs died, other ecosystems would also die. If there were no coral reefs, several species would not exist. Unreal conditions talk about imaginary or impossible situations. If the reefs died, other ecosystems would also die. Unreal in the present or future Note: Were is used for both singular and plural subjects. In fact, many coral reefs have been dying in recent years. This process is known as bleaching. Bleached coral reefs first turn white and then become dead brown coral. Sadly, some of the damage could have been avoided if more people had been aware of the negative effects of human activity such as pollution and over-fishing. Many experts agree that much of the damage we see today would have been prevented if there had been a greater effort to educate the public about the fragile reef ecosystem. 7 In unreal conditions in the past, would expresses a desired or predictable result. Could expresses a possible option. Much of the damage would have been prevented if there had been better education. Some of the damage could have been avoided if more people had been aware of the negative effects of pollution. Climate change is a major reason for the deterioration of coral reefs. If the ocean temperatures were not steadily rising, the coral reefs would be healthier. When water is too warm, corals expel the algae living in their tissues. This causes the coral to turn completely white. Corals can sometimes survive bleaching, but they are weaker and under more stress. The ocean temperatures are rising. Coral reefs are not healthy. Progressive verb forms are used in progressive situations. If the ocean temperatures were not rising, coral reefs would be healthier. Real situation: Conditional Statement: Climate change is not the only problem. Trash often ends up in the sea. These items can entangle and kill reef organisms and break or damage reefs. Plastics are especially hard on ocean life. Had the effects of plastics on marine life been better understood, we could have found alternatives to plastic sooner. Conservationists are working hard to clean up our seas. Otherwise, the problem would be much worse. However, in order to truly address the problem, we need to reduce the amount of plastic we use and throw away. Had we known, we could have prevented the problem. With were and had (past perfect), and should , sometimes if is omitted, and the subject and verb are inverted. Were more people aware of the problem, there would be greater progress. Had we known = If we had known Were more people aware = If more people were aware They are working to find a solution. Otherwise, the problem would be much worse. Often the if-clause is implied, not stated. Conditional verbs are frequently used following otherwise. If they weren’t working to find a solution Implied condition: 1. What would happen if there were no coral reefs? 2. What would you do if you had a chance tosave the coral reefs? 3. If you were able to travel anywhere in the world, where would you go? 4. Think about a regret or a mistake you’ve made. What could you have done differently? PRACTICE 1 – Ask Your Partner PRACTICE 2 Complete the sentence with the verbs in parentheses. 1. If I could travel anywhere in the world, I (go) _________________ to the Great Barrier Reef in Australia. 2. I (travel) ________________________ there last year if I had had enough money. 3. Jane would try scuba diving if she (be, not) ____________ afraid of swimming. 4. Had I known how fun diving is, I (try) ______________________ it sooner. 5. If the weather (be) _________ nicer, we would go out today. would go would/could have gone weren’t would have tried were $$