learn 表示“获悉，得知，听到”时，其后通常接从句。如：

Last week she learned that she was pregnant. 上个星期她得知自己怀孕了。

I later learnt (that) the message had never arrived. 我后来听说从来就没有收到过那个消息。

We were very surprised to learn (that) she had got married again. 我们听说她又结婚了，感到很惊讶。 

若后接名词或代词作宾语，则通常要接介词 of（有时也接 about）。如：

The wider world learned of his illness months after he told his family. 他把病情告诉了家人的多个月后外界才知道。

He learned about his appointment by telephone yesterday. 昨天他从电话里得知自己被任命的消息。

表示通过……得知，通常用介词 through：

I learned of the job through friends.  我通过朋友得知那份工作。

Bob learned of the contract through a story in the newspaper. 鲍勃从报纸上的一则报道知道了这个合同。

用于此义时通常不用介词by或on，若用介词 from，则表示“从……听说或获悉”。如：

I learned of her arrival from a close friend. 我从一个好友那里听说她到了。

I learned of your new address from your parents. 我从你父母那里知道了你的通讯地址。