You want to visit your grandparents, but the roads are flooded.
If only the roads weren't flooded, would visited your randparents.
You get lost easily because you don't have GPS inyour car.
If only you had a GPS, you wouldn't have got lost so easily.
You wanted to hire a Jeep on holiday, but you didn't have enough money.
If only you had enough money, you would have hired a Jeep on holiday.
You missed your flight because your taxi got stuck in the snow.
If only your taxi hadn't got stuck, you wouldn't have missed yor flight.