Second vs Secondly: Which One Is Correct in Formal Writing? Secondly is grammatically correct but sounds more formal and is now less common Examples: First, we reviewed the budget Second, we approved the plan Firstly, the policy affects costs Secondly, it impacts staff morale In most cases, second is clearer, shorter, and more natural
secondly | meaning of secondly in Longman Dictionary of Contemporary . . . From Longman Dictionary of Contemporary English sec‧ond‧ly ˈsekəndli S3 adverb [sentence adverb] used when you want to give a second point or fact, or give a second reason for something → firstly Firstly, they are not efficient, and secondly, they are expensive to make