Eva shouldn't have / didn't need to put on a party two days before New Year's Eve. Almost no one came.
shouldn't have
Why did I bother buying a big bottle of water? Samuel had already packed one. I didn't need to bother / shouldn't have bothered.
shouldn't have bothered
You must have made / must make more of an effort in class.
must make
You mustn't / needn't look at other students' work. It's against the rules.
mustn't
You mustn't be standing / mustn't stand on the desk. Otherwise, you'll break it.
mustn't stand
I think her book would / should have sold millions but the publishers thought it wasn't enough.
would
I worked fast and finished my essay on time but now the teacher has given the class 2 more weeks. // I ... so hard. (NEED)
needn't have worked
A: 'But it was an accident!' B: 'Well, you should / would have been more careful.'
should
We didn't dress up smartly because it wasn't necessary. It was a casual party. // We ... dress up smartly because it was a casual party. (NOT)
didn't need to
I think she was wrong to make a promise she couldn't keep // She ... a promise she couldn't keep. (NOT)
shouldn't have made
A: 'Why did you worry when I went bungee jumping?' B: 'You ... injured'. (GOT)
could have got
I bought a ticket but it wasn't necessary - I made a mistake. // I ... a ticket. (NOT)
needn't have bought / didn't need to buy/ shouldn't have bought
You gave the tour guide a tip but it was not necessary. // You ... give the tour guide a tip. (NOT)
didn't need to
It was a mistake for you to buy a dog. You ... a dog. (NOT)
shouldn't have bought
You should buy / have bought a better telescope with the money you'll get on your birthday. This one isn't very good.
buy
You're tired. You could / must have had a bad night's sleep.
must
