多年

汤姆是我多年的朋友。

Tāng mǔ shì wǒ duō nián de péng you.

Tom has been a friend of mine for years.

我父亲经营外贸多年。

Wǒ fù qīn jīng yíng wài mào duō nián.

My father has been engaged in foreign trade for many years.

这事发生在很多年以前。

Zhè shì fā shēng zài hěn duō nián yǐ qián.

It happened a long time ago.