I agreed to my husband taking another wife on certain conditions. How do I make sure those conditions are not forgotten?

Write the conditions down clearly and bring them to the court's attention, so that they do not remain a spoken promise. List specific items: the amount of monthly maintenance (nafkah), the home you live in, the children's school fees, and the rota (turn of nights). Vague conditions such as ‘be fair’ are hard to monitor. In matters of debt, Allah commands: “reduce them to writing” (Surah al-Baqarah 2:282); promises that touch a family's rights are also better preserved when written down. Present the list at the hearing or a sulh session, and ask whether it can be included in the order. Keep a copy of the order when it is issued. See conditions in a polygyny order.