Present Perfect and Past Simple (compared)

Present Perfect :  We use present perfect for a period of time that continues from the past until now. For example, today, this week, since 1990 etc.  The Present Perfect always has a connection with ‘Now ‘.

• The manager has lost his keys.  He can’t open the office.  (Here, we are not thinking of the past action.  We are thinking of the present result of the action.  He doesn’t have his keys with him now.)
• I ‘ve not seen him today.
• It hasn’t rained this week.
• Have you seen him this morning? (It is still morning)

Past Simple :  We use Past Simple for a finished time in the past.  For example, yesterday, last week, from 1980 to 1990 etc.  The Past Simple tells us only about the past.  Do not use present perfect ( I have done) when you talk about a finished time ( for example, yesterday/ten minutes ago/ in 1985/ when I was a child etc)

• The manager lost his keys yesterday.  He could not open the office.  (Here, we are thinking of the action in the past.  We don’t know from this sentence whether the manager has  the keys with him now.)
• The weather was nice yesterday.
• He left ten minutes ago.
• She ate a lot of sweets when she was a child.
• Did he see her this morning? ( It is now afternoon or evening)