My father in law died 6 months ago.

My father in law died unexpectly 6 months ago. That broke my partner's heart, i'm always there for him, listening or just hugging him when he cries. He says that I help a lot but I don't want him to get depressed, he cries everyday and I don't know what to do, I've never been in that situation and sometimes I don't know what to say but just hug him. Any advise?