1.On the grounds of spending a lot,he is in debt.(On the grounds of+N/V-ing:vì)
2.We look forward to seeing you here again next year.(look forward to+V-ing:mong chờ làm gì)
3.John blamed the mistake on his serectary.(blame sth on sb:đổ lỗi cho ai)
4.Mình nghĩ đề là:Their work is bad because they have no training.
->If they had training,their work weren't bad.