以致于

wǒ tài lèi le yǐ zhì yú lì kè shuì zháo le

我太累了以致于立刻睡着了。

I was so tired that I fell asleep immediately.

wǒ xǐ chū wàng wài yǐ zhì yú wàng le yuē dìng

我喜出望外以致于忘了约定。

I was overjoyed so that I forgot the appointment.