More about the present perfect

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We also use the Present Perfect to talk about several different actions which have occurred in the past at different times. Present Perfect suggests the process is not complete and more actions are possible.Examples:The army has attacked that city five times.I have had four quizzes and five tests so far this semester.We have had many major problems while working on this project.She has talked to several specialists about her problem, but nobody knows why she is sick.Time Expressions with Present PerfectWhen we use the Present Perfect it means that something has happened at some point in our lives before now. Remember, the exact time the action happened is not important.Sometimes, we want to limit the time we are looking in for an experience. We can do this with expressions such as: in the last week, in the last year, this week, this month, so far, up to now, etc.this was seached by wikipedia.