What's the conditional?
Yaroslav isn't stupid, but he failed his midterm exam. Why? -- He didn't study for it.
"If Yaroslav had studied, he probably wouldn't have failed his midterm exam."
I'll try to give your message to Andrew, but I'm not sure whether I'll see him or not.
"If I see Andrew, I'll give him your message."
Mathew wants to go to the movies but doesn't have any money.
"If Mathew had some money, she would go to the movies"