GRAMMAR CONDITIONALS CONDITION CONSEQUENCE EXAMPLE Zero Conditional: cause-effect relationship, general truths If* + Present Simple Present simple If you give instructions to a computer, the computer executes them. First Conditional: likely situations in the future If + Present Simple Will + bare infinitive** If there are no mistakes in the code, the program will work. Second Conditional: improbable or impossible situations in the future If + Past Simple*** Third Conditional: situations which did not happen (impossibility in the past) If + Past Perfect Would + bare infinitive Would have + past participle If computers spoke English, programming languages would not/ wouldn t be necessary. If I were you, I would/ d write computer games. If you had/ d checked your code more carefully, there would not /wouldn t have been any syntax errors. * unless (= if not) is used for a negative condition; the verb following unless is affirmative. ** infinitive without to. *** with the verb be, in formal English, the form were is used for all the persons. 5 Complete these First Conditional sentences with the correct forms of the verbs given. 1. If there ................................ (be) no operating system, a computer ................................ (not work). 2. If the user ................................ (interact) with the computer in real time, the computer ................................ (respond) immediately to the input. 3. If different users ................................ (use) the same computer system at the same time, resources and ACTIVITIES time ................................ (be) shared among the users. 4. If you ................................ (want) to use different operating systems simultaneously, your computer ................................ (need) a virtual machine operating system. 5. If companies ................................ (buy) a good operating system, workers and employees ............................... (work) more efficiently. 6 Rewrite these sentences using unless. 1. 2. 3. 4. 5. If you don t use an interpreter or a compiler, the computer will not understand your program. If you don t install an operating system, the computer won t work. If you don t make mistakes, your program will run. If you don t have a graphical user interface, you ll have to learn a list of commands. If you don t update your operating system, your computer won t work properly. 140 Module 3 DEBUGGING