C1/C2 Modals - Didn't need to vs Needn't have

Yesterday was Saturday, so we .....

The previous owners had already decorated the flat, so we______ it ourselves.

The word 'should' in the lyric is used to express ....

The plane was late. I.................. to the airport so early.

The word 'let' in the title is used to express ....

It wasn't sunny so I _______________ sunglasses

Service was included in the bill, so you________ the waiter. It was a waste of money.

Thanks, but I already have an iphone. You.....

I didn't realize it was free to enter the museum so I ...............

I knew the grammar very well so I....

We ................ because we ordered takeaway food.

You.............................. I ate on the plane.

It's not raining. You........................ an umbrella.

Sandra ________ the clothes because Sue had already done that.

I ________ last night as I knew you were going to have dinner with them.

My mother gave me some money so I .................................