My in-laws are Bruneian and very particular about custom and polite language. How do I adapt without putting a foot wrong?

Make your husband your first teacher of custom, and ask before you guess. Even though our languages are closely related, every society has its own ways of greeting, using titles and behaving as a guest. Ask your husband to explain what his family is most careful about, such as how to address elders and manners at the dining table. Watch how your in-laws behave, and follow the good examples. If you make a mistake, apologise briefly and sincerely; most elders appreciate a daughter-in-law who wants to learn. Avoid comparing their customs with your family's in front of them. See Muslim families in Brunei.