I'm sure he confused me with someone else, cause I don't know him.
He must have confused me with someone else, cause I don't know him.
Maybe the dog was too tired to swim, so it decided to stay on the lilo.
The dog may/ might/could have been too tired to swim, so it decided to stay on the lilo.
I'm certain that someone really wanted to hide his money somewhere. That's why they created this belt.
Someone must have really wanted to hide his money somewhere.
It's impossible that you've eaten the whole cake in one go.
You can't/couldn't have eaten the whole cake in one go.
I wish I had been more careful with my phone.
I should have been more careful with my phone.
He had all chances to get there on time if there hadn't been a traffic jam.
He would/could have got there on time if there hadn't been a traffic jam.
It was a big mistake to accept such a terrible job offer!
He shouldn't have accepted such a terrible job offer!
I don't believe that it was her first painting.
It can't/couldn't have been her first painting.
I'm sure it was a lot of fun to make all this mess.
It must have been a lot of fun to make all this mess.
It was unnecessary to dress him so warmly.
They needn't have dressed him so warmly.
He had all chances to win but his sister distracted him and he lost.
He would have won if his sister hadn't distracted him.
She would be thinner if she had attended a fitness club.
To be thinner, she should have attended a fitness club.
If only I had taken my credit card with me, cause there's not enough cash to buy everything I want.
I should have taken my credit card with me, cause there's not enough cash to buy everything I want.
He probably didn't see the notice saying that the bench was freshly painted.
He may/might not have seen the notice saying that the bench was freshly painted.