Use of Present Perfect Simple:
for actions which happened at an unstated time int the past. The exact time is not mentioned because it is not important
Kim has bought a new house
for actions which started in the past and are still continuing in the present
She has been a teacher since 2001.
for actions which have recently finished and their results are visible in the present.
They have washed their car.
with today, this morning etc. When these periods of time are not finished at the time of speaking
She has typed four letters this morning.







