I count myself lucky to have known him.
和他相识，我觉得很幸运。
I'm lucky in that I've got four sisters.
我很幸运，因为我有四个姐妹。
Luckily there was a taxi rank nearby.
幸好附近有个出租车候客处。
Luckily, my mother rose to the occasion.
幸好，我母亲挺身而出作了处置。
He's been very unlucky that no chances have fallen to him.
他很不走运，没有任何机会落到他身上。