The sentence that begins with if known as conditional sentence.
Remember, had, were, in case, unless, provided, provided that, providing that, when can be used instead of If.
Try to understand If Clause and Main Clause
|If Clause||Main Clause|
|1. If I wake up early,||I go jogging.|
|2. If I have enough money,||I will go to Japan.|
|3. If I have enough time,||I’ll watch the football match.|
|4. If I had wings,||I would fly.|
|5. If I had time,||I would drop you off at school.|
|6. If he had been careful,||he wouldn’t have had that terrible accident.|
|Main Clause||If Clause|
|1. I go jogging||If I wake up early.|
|2. I will go to Japan||If I have enough money.|
|3. I’ll watch the football match||If I have enough time.|
|4. I would fly||If I had wings.|
|5. I would drop you off at school||If I had time.|
|6. He wouldn’t have had that terrible accident||If he had been careful.|
There are four types of Conditional sentences
|Conditional||Usage||If clause||Main clause|
|1. Zero||General truths||Simple present||Simple present|
|2. First||possible and very likely||Simple present||Simple future
|3. Second||possible but very unlikely||Simple past||subject+would/could/might+verb1|
|4. Third||impossible to fulfill||Past perfect||subject+would/could/might+have+verb3|
Four types of Conditional sentences in details
|Zero conditional||If + Simple present + Simple present|
|First conditional||It is possible and very likely that the condition will be fulfilled.
If + Simple present , sub + shall/will/can/may + verb1 + ext.
If + Simple present, Imperative sentence
|Second conditional||It is possible but very unlikely, that the condition will be fulfilled.
If + Simple past , sub + would/could/might+ verb1 + ext.
Or, Were I a bird, I would fly at large.
Or, Had I enough money, I would start a business.
|Third conditional||It is impossible that the condition will be fulfilled.
If +past perfect, sub + would/could/might+have+verb3+ext.
Or, Had I seen her before, I would have disclosed the truth.
|If my husband has a cold, I usually catch it. If public transport is efficient, people stop using their cars. If you mix red and blue, you get purple. If this thing happens, that thing happens. If people eat too much, they get fat. Snakes bite if they are scared. If babies are hungry, they cry If you cross an international date line, the time changes. If it rains, the grass gets wet. Wood doesn’t burn if there is no air. If you do not exercise, you gain weight. If I don’t study, I don’t do well on tests. If you are not on time, you lose one mark. If it rains, tennis lessons are held in the gym. If Rana is out of the office, I take his calls. If you heat ice, it melts. Ice melts if you heat it. When you heat ice, it melts. Ice melts when you heat it. If it rains, the grass gets wet. The grass gets wet if it rains. When it rains, the grass gets wet. The grass gets wet when it rains. If you freeze water, it becomes a solid. Plants die if they don’t get enough water. If water reaches 100 degrees, it boils. You get water if you mix hydrogen and oxygen. If you touch a fire, you get burned. People die if they don’t eat. If I eat peanuts, I am sick.
The zero conditional is also often used to give instructions, using the imperative in the main clause.
If Ashraf phones, tell him to meet me at the cinema. Ask me if you’re not sure what to do. If you want to come, call me before 5:00. Meet me here if we get separated. If he gets there before me, ask him to wait. If you leave the room, turn off the lights. Enter through the left if you have your ticket already.
If I invite you, you (come). If it rains, I (not go) to school. If I want, he (give) me. If they ask, he (disclose). If I (see) him, I will call him. If you run in the rain, you (catch) cold. If you work hard, you (prosper) in life. Memory will not go out if it (rain). If you finish the work in time, you (get) a prize. If they come, I (be) happy. If you write the letter, I (post) it. If it (rain), I will not go to play. If he reads attentively, he (pass). If it rains, I (go) to the park. If I study today, I (go) to the party tonight. If I have enough money, I(buy) some new shoes. She (be) late if the train is delayed. She (miss) the bus if she doesn’t leave soon. If I see her, I (tell) her.
If her uncle (arrives), I would meet him. If I (know) her phone number, I would call her. If I got a student visa, I (get) a great chance to study abroad. If I (am) a king, I would help the poor. If you (come) here, I would give you the news. If he studied regularly and seriously, he (do) well in the examination. If I were a king, I (help) the poor. If he requested me, I (go) there. If they tried, they (succeed). If I were a bird, I (fly). If he came, I (go). If I had enough money, I (set) up a hospital. If you tried, you (do) it. If I had extra books, I (lend) him. If I had the wings of a Dove, I (fly) to you.
If he had studied very seriously, he (make) a bright result. If she had not missed the interview, she (get) the job. If I had had your number, I (call) you but I had forgotten it. I (order) a taxi if you had told me. I would not have said that if I (have) there. Had I the wings of a bird, I (fly) like a bird. If I had been a rich man, I (help) the poor. Had I been a rich man, I (help) the poor. We would have come, if he (invite) us.