He is very weak, for he has been ill for a long time.

他病了很久，身体衰弱。

《新英汉大辞典》

He has been ill until recently.

他最近一直生病。

youdao

He has been ill for a week.

上周他的妻子突然生病了。

youdao

Reagan says almost from the time his father first learned he was ill, he has been part of a national campaign to raise public awareness about this devastating and heartbreaking illness.

VOA: standard.2009.12.04

Haas has also been ill and taking antibiotics, so he might not be at his best against Sock.

WSJ: At the French Open, Jack Sock Is Having a

Stoner, who has been plagued by ill health in recent weeks, told BBC Sport he too was happy with his showing.

BBC: Rossi leaves it late to take pole

Ever since Greg Pullman, founder and owner of Pullman Coffee Tampers in Adelaide, South Australia, resized the ill-fitting tamper for the his new coffee machine in 2002, he has been fixated on the process.

BBC: The new 'Australian made'