Language Check Point
Don’t say: I am here since last week
Say: I have been here since last week.
Note: An unfinished action has to be in the present
Don’t say: When I woke up my roommate left the room already.
Say: When I woke up my roommate had left the room already.
Note: The action that occurred before the second action has to be in the past perfect tense.
Don’t say: My mom has called me yesterday.
Say: My mom called me yesterday.
Note: The present perfect tense cannot be used with an expression of past time.