The rules
- After words that demand or require something, use the plain base form of the verb for every subject: The rules require that he wait; it is essential that it be dry.
- For something untrue in the present, use were for every subject: If I were taller, I could reach the shelf.
- For something untrue in the past, put had in the if-clause and would have in the result, and never put would in the if-clause: If it had rained, the river would have risen.
- Use the past perfect for an action finished before another past moment: By the time we arrived, the bus had left.
- Use the present perfect for time that runs up to now, and the simple past with a finished time: She has lived here since 2010; she moved here in 2010.
- After a past reporting verb, will becomes would: He said that the shop would open at ten.
- Use the passive when the subject receives the action, and make the verb agree with its true subject, not a nearby noun: The temple was built in 1702; the list of rules is long.
This time: 0 right, 0 wrong