This letter to Jane proved almost impossible now that it came to the point.

The letters proved that, and the fact that there'd been three of them in so short a time.

Better to let someone else take the blame if the letter proved to be worthless.

Some federal law enforcement officials said they were growing doubtful that the letter would prove to be contaminated.

The letter which she wrote on this occasion to her sister, will prove what she felt.

A letter which was found in 1989 proved an invitation to invade did indeed exist.

This letter was proving to be a lot more enlightening than he'd had any reason to expect.

Any letters that might fall into unfriendly hands would thus prove useless.

On the white surface the letters proved hard to see, but they clearly had been carved there.

Both produced witnesses and letters to prove their cases.