他听到好消息时，顿时兴奋起来。

Tā tīngdào hǎo xiāoxi shí, dùnshí xīngfèn qǐlái.

When he heard the good news, he immediately became excited.

他们听到突然的消息，顿时慌乱起来。

Tāmen tīng dào tūrán de xiāoxi, dùnshí huāngluàn qǐlái.

They heard sudden news and immediately became flustered.

他看到老朋友，顿时笑逐颜开。

Tā kàn dào lǎo péngyǒu, dùnshí xiào zhú yán kāi.

When he saw an old friend, he immediately smiled with joy.