Interrogative adverbs are an essential part of Estonian grammar, as they help form questions and gather information. In Estonian, interrogative adverbs usually appear at the beginning of a sentence and can be used to ask various types of questions, such as those related to time, place, reason, and manner. Some common interrogative adverbs in Estonian include “millal” (when), “kus” (where), “miks” (why), and “kuidas” (how). By mastering the use of interrogative adverbs, students can significantly improve their Estonian communication skills.