中文原文：

他亲笔写了这封信。

错误译文：

He wrote the letter with his own pen.

正确译文：

1) He wrote the letter himself.

2) He wrote the letter in his own hand.

翻译加油站：

“亲笔”是“亲自动笔”的意思。而with his own pen的意思是“用他自己的笔”。“亲自”和“亲身”可以译为oneself，in person, personally 等。例如：她亲身经历了这个事。She experienced the event herself/in person /personally.

“亲眼”、“亲耳”、“亲口”和“亲手”都有一个身体部位名词，译成英语可以用 with one's own + 身体部位名词(eyes, ears, mouth, hands) 表示。例如：这位外国朋友亲眼看见了中国近年来发生的巨大变化。The foreign friend saw with his own eyes the great changes that had taken place in recent years in China.妈妈亲手给我做了一碗面条。My mother cooked a bowl of noodles for me with her own hands.我简直不能相信我亲眼所见和亲耳所闻的事情。I could hardly believe what I had seen with my own eyes and heard with my own ears.