Grammar: Present, Present Perfect, and Past
The same information can be expressed in different ways. Consider three situations: A, B, and C:
Just the facts. no time mentioned (present perfect).
A) They’ve closed the centre to traffic.
B) Someone’s eaten all the cake!
C) The government have changed the drinking laws.
Specification of time in the past (past tense).
A) They closed the centre to traffic yesterday.
B) Someone ate the cake while I was out.
C) Last week, the government announced changes in the drinking laws.
Present situation, result of past action (present tense).
A) The city centre is closed.
B) The cake is finished.
C) The drinking laws are now different.