There is a clue that weekly quests stack on the Weekly Quests screen (bottom left corner) but I'm not sure about the mobile version. And I understand that some of the wording used in the game is not the best but I think it's a part of the puzzle. It definitely mimics communication challenges of real life. What might be easy to understand to some, others might find it difficult. Either way, I don't think there is such a things as perfect wording.