我很失望。
Wǒ hěn shīwàng.
I'm very disappointed.
别失望。
Bié shīwàng.
Don't be disappointed.
我对他失望了。
Wǒ duì tā shīwàng le.
I've lost hope in him.
她开始失望。
Tā kāishǐ shīwàng.
She began to lose hope.
