Составьте предложения использую Past Perfect и past simple. Помогите пожалуйста

He went to the seaside last year He had gone to the seaside by the end of the year They went sightseeing after we came to the city We had gone sightseeing when we stayed in London We was aboard in 2005 He had been aboard before he entered college He saw deferent historical monument during his..... I had seen different historical monument before I began .....