Answer:
1. You shouldn't walk on = correct
You shouldn't to walk = incorrect
2. Mark should meets = incorrect
Mark should meet = correct
3. We shouldn't call an ambulance = incorrect
We should call an ambulance = correct
4. Should send Amanda = incorrect
Should Amanda send = correct
5. We should go back home = correct
We shouldn't go back home = incorrect
6. Should Jason buy a new car? = correct
Should Jason buys a new car? = incorrect