it was difficult for him/her
He was having trouble breathing.
Por eso le costaba tanto irse.
That’s why it was so hard for him to leave.
— Los lunes al sol (2002)
A Tom le costaba creer que no le gustaba en lo más mínimo a Mary.
Tom found it hard to believe that Mary didn't like him in the slightest.
Le costaba mucho terminar su trabajo.
He had a lot of trouble finishing his work.
A Tom le costaba hacer amigos.
Tom had trouble making friends.
Le costaba ocultar su orgullo por su éxito.
He found it difficult to hide his pride in his success.