http://www.englishforums.com/search/pro.htm?q=tag%3aNumbers+tag%3aPresent+perfect+tag%3aArticlesSearch results for 'tag:Numbers tag:Present perfect tag:Articles' matching tags 'Numbers', 'Present perfect', and 'Articles'en-USCSMOD (Build: 3273.32735)http://www.englishforums.com/English/SinceIHaveWrittenOrWrote/dxzhb/post.htm#320910Sun, 28 Jan 2007 12:27:49 GMT946f00bb-57d3-4b7b-a9a2-059b5341af52:320910ant_222I guess have written can be ok Like It was the last time I have written an article EDIT maybe it s being the last time is considered as a sort of connetion with the present thus making Present Perfect fit By the way a google search returned equal numbers of entries of 1 it has been a while since I have written 2 it has been a while since I wrote EDIT2 But in the following sentence I think only Past Simple is correct 171 We have seen him several times since he suffered the crash 187 http://www.englishforums.com/English/SentenceQuestionsThankYou/chhrd/post.htm#203459Sun, 05 Mar 2006 19:52:33 GMT946f00bb-57d3-4b7b-a9a2-059b5341af52:203459demetrius WANG CHUN wrote 1 Ancient and modern human beings use their great intelligence to invent machines that help people lead a comfortable and convenient life My problem with this sentence is that it is not possible for ancient human beings to do anything any more so using the present tense just doesn t sound right Other than that there is nothing wrong with the grammar It could be fixed by changing to the present perfect have used but not without changing the meaning WANG CHUN wrote 2 What is a colossal distinction between humankind and machines is that former is learning animal and latter is like a robot One colossal distinction between humans and machines is that the former are learning animals and the latter are like robots 1 You cannot use What is here 2 Humankind is a singular collection A collection cannot be an animal or animals 3 You must use the definite article with former and latter 4 As humankind has changed to humans the number of is and animal changes to plural By the way it would have to have been a learning animal not learning animal 5 machines is plural so is should be are and robot should be robots WANG CHUN wrote 3 It is James Watt who had the intelligence to invent the use of steam for power and improve a steam engine that began the Industrial Revolution in which people saw these machines as a tool that enabled them to improve all aspect of lives It was James Watt who had the intelligence to invent steam power and improve the steam engine which began the Industrial Revolution in which people saw these machines as tools that enabled them to improve all aspects of their lives 1 It must be It was James Watt to agree with who had 2 to invent the use of steam for power sounds unnatural and clumsy It is better to simply write to invent steam power 3 It should be the steam engine 4 It should be which began not that began because we are not trying to restrict steam engines to specify the one that began the Industrial Revolution 5 a tool must agree in number with machines 6 aspect must be plural to agree with all 7 You need a possessive pronoun their to refer back to the people whose aspects of life were changed WANG CHUN wrote 4 All technological innovations can be described as an implement of human intelligence helping people to live a comfortable life All technological innovations can be described as implementations of human intelligence helping people to live a comfortable life 1 an implement must agree in number with innovations 2 Implements is the wrong word I m not happy with implementations either really but it is the closest in sense