A.Wallwork - English for Research Usage, Style, and Grammar - 2013
14.15 for, since, from (time) The adverb of time you use will normally help you to understand the correct tense to use (Section 8 ). 1. For indicates the duration from the past until the present. It is typically used with plural words indicating time, e.g. days, months, years, decades . for answers the question how long has this situation been ongoing In this sense, for is used with the present perfect . Similar expressions denoting a duration from past to present are over (e.g. over the last two decades ), so far, until now ( 8.17 ). 2. If for is used to indicate a period of time that is now finished, then it is used with the simple past. 3. Since indicates the starting point of a current situation. It is typically used with precise points in time, e.g. 2001, last month, yesterday . since answers the question when did this situation begin 4. Fromindicates a range of time, i.e. with a start and finish. Because there is a finish time, from is not used with the present perfect . But from can be used with most other tenses. YES NO 1 Web have been doing this research for nine years. Web dob this research from / since nine years. 1 Over the last few months there has been a lot of media coverage. Over the last few months there is a lot of media coverage. 2 I studiedin Boston forthree years and then I moved to Beijing. I have studied in Boston for three years and then I have moved to Beijing. 3 Since 2001 there has been a dramatic increase in suicides. From / Since 2001 there is a dramatic increase in suicides. 4 I studied in Boston from 2008 to 2011 . I have studied in Boston from 2008 to
