Present Perfect Passive

First

Last

First

Last

just

already

for ever

still

maybe

Something done yesterday

Recent actions

Something done in the future

Unfinished actions, continues today

The student has just finished his homework.

The student finished his homework yesterday.

The homework has been just done by the student.

The student will do his homework tomorrow.

For years plants have been used by people as medicine.

People have used plants as medicine for years.

Medicine was used by people for a long time.

For years plants has been used by people as medicine.

For years plants have been used by people as medicine.

People have used plants as medicine for years.

Medicine was used by people for a long time.

For years plants has been used by people as medicine.

Unfortunately some useful plants were lost

Unfortunately some useful plants have been lost by people

Unfortunately some useful plants has been lost by people

Unfortunately some useful plants were lost by people

Sub+have/has+been+V3+ (by) obj

Obj+have/has+been+V3+ (by) sub

Obj+have/has+V3+subj