River ThamesThames – Isle of Dogs If CLAUSES River Thames Thames – Isle of Dogs CONDITIONAL SENTENCES If human beings go on modifying the environmental cycles they will stop the ability of ecosystem to provide benefits to humans. CONDITIONAL SENTENCES Gases in the atmosphere keep the sun's heat in and help make our planet livable. If we stopped this natural insulation, the Earth's surface would be much colder than it is now. CONDITIONAL SENTENCES Look what we've done!!! Society's Impact On Our Environment We would have found more trees like this every where if we had used common sense. The Greenhouse Effect wouldn’t have become a big problem if we had not cut down so many trees. There are three types of conditionals. Each type consists of two parts: the if -clause (hypothesis), which begins with the word if. and the main clause, which shows the result of the hypothesis. if - clause (hypothesis) main clause (result) If we change our habits , we will save our planet. When the if-clause comes before the main clause, they are separated with a comma. IF we didn't cut them down, trees like these would be almost every where When the main clause comes before the if-clause, then they are not separated with a comma. Trees like these would be almost every where if we didn't cut them down Type 1 Oração Condicional Simple Present If we use less energy , Oração Principal Simple Future we will help the greenhouse effect getting worse. read about it and you’ll find out. If you don’t know what the Greenhouse Effect may cause, TYPE 1- Conditionals If we use less energy we will help the greenhouse effect getting worse. Type 1 conditionals can also be formed as follows: If - clause If + Simple Present Main Clause Simple Present Imperative Can / must / may ... + bare infinitive If + Simple Present + Simple Present If you think our radiation is low, you're wrong! If + Simple Present + Imperative If you want to find out how to help our planet, click below on the link "Ways You Can Help." If + Simple Present + Modal Verb If we carry on polluting the atmosphere with greenhouse gases, it can cause very dangerous effects on the Earth. Type 2 If Clause Simple Past Main Clause Simple Conditional would + infinitivo (- to) If the temperature became the water of the seas and higher, oceans would expand. If I were you, I would become a “Healthy planet member”. TYPE 2- Conditionals Grass like this would be everywhere if we did not make so many roads and houses. If each of us saved just one can a day from landfill - that would add up to hundreds of millions of cans - in just one day. Type 3 If Clause Past Perfect Main Clause would have + particípio If we had formulated global temperature specific policy to control wouldn’t have increased. human activities, If we had reduced the use of fossil fuels, we would have reduced acid rain. If I had run the dishwasher only with a full load, we would have reduced the use of electricity. We would have helped to protect the environment if we had used more recycled materials. We can use unless instead of if...not in the , if -clause. The verb is always in the affirmative after unless. (UNLESS = a não ser que) lf we don't follow the Kyoto and Bonn treaties , we'll have serious environmental problems. Unless we follow the Kyoto and Bonn treaties , we'll have serious environmental problems.