Jim didn't lend me any money so I was unable to buy the car.

• If Jim had lent me some money, I would have been able to buy the car.

He rarely met such a beautiful film star.

• Rarely did he meet such a beautiful film star.

Though he was poor, he wasn't always unhappy.

• Despite being poor, he wasn't always unhappy.

She can't ask intelligent questions. She can't profit from listening to her colleagues.

• She can neither ask intelligent questions nor profit from listening to her colleagues.

He spoke English very carefully. He spoke very clearly.

• He not only spoke English very carefully but also very clearly.

Gravity makes balls thrown into the air fall back down.

• If there weren't gravity, balls thrown into the air wouldn't fall back down.