'当然 (dāngrán)' is a common word in Mandarin Chinese that is used to express a strong affirmation or agreement. This can be used to answer a question, express one's own opinion, or affirm someone else's statement. It conveys a sense of certainty and can often give emphasis in a conversation. By using '当然', you can easily convey your agreement with someone else's opinion or reassure others of a certain fact.