Hey there! :)
Anwer:
1 Be careful. We paid (pay) a lot of money
for that vase.
6 She left (leave) an hour ago.
2 David shouted (shout) at his brother this morning.
7 Sam knocked (knock)at the door but no one was in,
3 Mary spent (spend) €35 on a new book.
My sister didn't sing (not/sing) at the concert last Saturday.
4 Our teacher said (say) that the class was very good today.
9 My sister walked (walk) to school yesterday.
They met on holiday last year.
10 My friends decided (decide) to stay in and watch
a film last night.
Hope this helps! :)