If only I lost/ hadn't lost/ didn't lose my camera on the beach.
hadn't lost
It's high time we stop/ stopped/ had stopped dumping waste in the seas.
stopped
My back's all red. I wish I had/ did put more sun cream on.
had put
I'd rather she didn't/ won't go alone, to be honest
didn't go alone
If only I hadn't to/ had to/ didn't have to go camping. I hate sleeping in tents.
didn't have to go camping
I wish you all knew/ had known/ know just how much effort I put into this trip.
knew
If only I had seen/ saw/ did see her earlier.I'd have asked her to join us.
had seen
I'd rather we use/ used/ had used less plastic than we currently do.
used
If only the fire doesn't destroy/ didn't destroy/ hadn't destroyed the forest.
hadn't destroyed
I wish supermarkets ... (sell) fruit and vegetables wrapped in plastic
didn't sell
We all contribute to pollution. It's high time we ... ( recognise) that fact.
recognised
It sounds like the lecture you attended was fascinating. I wish I ( know) about it.
had known
I'd rather we ... (discuss) the issue right now if you don't mind
didn't discuss
