Wǒ pà nǐ méi fǎ gēn tā jiéhūn. I'm afraid you can't marry her.
Tā bù huì chéng fēijī yīn wéi hàipà zhuì jī. She won't take an airplane for fear of a crash.
I'm afraid of earthquakes.
Tā shuō tā pà tiān huì xià yǔ. He said that he was afraid it would be rainy.
Kǒngpà jiù zhè diǎn shàng, wǒ hé nǐ chí bùtóng yìjiàn. I'm afraid I differ with you on this point.