ciężko (gdy coś jest dla kogoś trudne)
He works very hard.
It's hard to sing and dance at the same time.
It's hard for me to get up at 5:30 a.m.
It was very hard for him to find a job.
It's hard to imagine that people would do that for money.
Przysłówka "hard" nie należy mylić z przysłówkiem "hardly", oznaczającym "ledwo, prawie nie".