Present Perfect vs. Simple Past


I. Indefinite Time vs. Definite Time

The present perfect is usually used to express indefinite time (not specific), and the simple past is usually used to express definite time (specific).


Indefinite Time Definite Time

Mr. March has visited New York many times.

Mr. March visited New York two months ago/in July/last year/in 1998.

Bill has talked to Professor Hughes several times.

Bill talked to Professor Hughes yesterday.

Ann has recently purchased a house.

OR

Ann has purchased a house recently.

Ann purchased a house last month.

Doris has been very busy lately.

Doris was very busy yesterday.



II. Period Continues to Present vs. Period Ended in Past

We use the present perfect with for or since to indicate a period of time that continues to the present; the time period is not finished.

We use the simple past to indicate a period of time that began and ended in the past; the time period is finished.

We use for with an amount of time (for two hours, for three days, for six weeks, for ten years, for a long time).

We use since with the beginning of the time period (since January, since 1995, since last summer, since I graduated).


Period Continues to Present Period Ended in Past

Mr. Lee has worked for Boeing since 1990/since he graduated from college.

Mr. Wright worked for Lockheed from 1990 to 1995.

Mr. Lee has worked for Boeing for 14 years. (He still works for Boeing.)

Mr. Wright worked for Lockheed for five years. (He no longer works for Lockheed.)



III. Possibility of Performing Action vs. No Possibility of Performing Action

We use the present perfect to talk about an action that has not been performed yet, but might be performed at some future time. We use the simple past when there is no possibility of performing the action at some future time.


Possibility of Performing Action No Possibility of Performing Action

President Bush has never visited Mexico. (It is still possible for him to visit at some future time.)

President Reagan never visited Mexico. (It is not possible for him to visit at some future time because he is no longer living.)



Back to Grammar Page
This page was last modified on 06/15/10

Free web hostingWeb hosting