I am Mexican-American and know what I'm talking about. You use the spanish forms of "to do" and the PAST participle of the word, in the case of number 1, "han llegado" means "have arrived." You repeat this process until you finish.
Well, if you want the answer for "I would tell them to know what they want to do before going to college", then it's " Les diría que sepan lo que quieren hacer antes de ir a la universidad "
