Student or Learner
Both have the same meaning? Or is there any difference?
(A) The harbor can be blocked.
(B) The harbor could be blocked.
'Could' can also be used simply as the past tense of 'can', especially in reported speech.
If we don't carry out regular dredging operations, the harbour can be blocked.
The harbour master told is that if they didn't carry out regular dredging operations, the harbour could be blocked.