Hi Danyel, "He told them to go to the restaurant" means he instructed them to do this action. "He told them they would go to the restaurant" (notice I added the object "them") means he let them know that they would be doing this action. He may or may not have specifically instructed/directed them to, unlike the first sentence which means he definitely directed them to do so. I hope my explanation was clear. If not, please let me know.

Hello Danyel He told them to go to the restaurant is describing an order/suggestion - You should always use a personal object noun (or pronoun) after the verb 'tell' (apart from certain fixed expressions) You can't use 'they' after tell because this is a subject pronoun, but you can use it after say - He said they would go to the restaurant. This is less strong/forceful than 'tell' Hope this helps Bob