It's a pity I can't help you now.
→ I wish I could help you now.

"Why didn't you make up your mind before?" he asked me.
→ He asked why I hadn't made up my mind before.

We were too late to do anything.
→ Everything was too late to do.

"Would you mind not parking there?"
→ I'd rather you didn't park there.

I would rather...
→ I would rather you hadn't asked me.

It's worthless painting the room.
→ There is no point in painting the room.

I haven't played tennis for 6 years.
→ The last time I played tennis was 6 years ago.

Keeping calm is the secret of passing your final test.
→ As long as you keep calm, you will pass your final test.

The train had left before we arrived at the station.
→ By the time we arrived at the station, the train had already left.

She left for Hà Nội Capital, but right after that it began to rain.
→ Hardly had she left for Hà Nội Capital when it began to rain