In this post I will discuss about common mistakes while using verbs in sentence through some examples.
Incorrect: We have finished the task a week ago.
Correct: We finished the task a week ago.
Incorrect: They have visited him yesterday.
Correct: They visited him yesterday.

Adverbs cannot be used with present perfect tense because it refers to a specific point of time in the past. Use simple past tense while writing about something happened in the past.
Correct: We saw her yesterday.
Incorrect: I had gone to the movie last evening.
Correct: I went to the movie last evening.
You can only use past perfect tense to suggest an action finished before another action initiated.
For example, you can say: I had eaten my dinner before I went to the movie last night. (Done)
Incorrect: I had spoken to the boys about my holiday.
Correct: I have spoken to the boys about my holiday.

Incorrect: He hanged the pictures on the wall.
Correct: He hung the pictures on the wall.
Incorrect: The terrorist was hung.
Correct: The terrorist was hanged.
Use hanged to talk about execution by hanging.