Tham khảo tài liệu 'longman english grammar practice_8', ngoại ngữ, anh ngữ phổ thông phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | For more material and information please visit 14 Conditional sentences Mixed conditionals unless if. not etc. Mixed tenses in conditional sentences LEG Study We do not always have to stick rigidly to the three types of conditional sentences . There are occasions when we can use any tenses in if-clauses depending on the context If 1 am as clever as you say 1 am 1 would have been rich by now. Type 1 Type 3 g If you knew me better you wouldn t have said that. Type 2 Type 3 1 If 1 had had your advantages I d be better off now. Type 3 Type 2 p . it Write Use mixed tenses in these sentences. 1 If I .won . be you I check my facts before I wrote that letter. 2 If you. be so hungry you. not miss breakfast. 3 If he. not catch the train he. not arrive for another two hours. 4 He. feel very tired today if he. play rugby yesterday. 5 If the snake bite. be poisonous you. feel very ill now. 6 If I. be in your position I. answer his letter by now. If not and unless LEG Study ÍÃÃ3 1 We can use if. not and unless in place of each other when we are saying except if . Unless is stronger than if not and we sometimes use it in threats If you don t change your mindI won t be able to help you. Except if you change . Unless you change your mind I won t be able to help you. Except if you change . 2 We cannot use unless in place of ifnot when if not doesn t mean except if 111 be surprised if he doesn t win. ifnot doesn t mean except if She d be better company if she didn t complain so much. if not doesn t mean except if 3 We often use unless never if. not to introduce an afterthought I couldn t have got to the meeting - unless of course Ihad caught an earlier train. Write 1 Tick the sentences where we could use either if not or unless. 1 I won t do it if you don t help me. 2 Unless he chooses his words more carefully he ll be in 3 She d have more friends if she didn t criticise everyone so 4 111 be surprised if .
