How to Respond to Someone on Instagramby David Wayne
Interacting with other Instagram users through comments and “likes” helps you expand your profile and attract followers. When a user comments on your picture or mentions your name in a comment, you're notified through Instagram, and you can reply directly to the user by mentioning her username in your comment.
Mention a User in a Comment
When you receive a notification that another user has commented on your picture or mentioned your name, you can tap and hold her username to bring up a response menu. Select “Mention User” from the menu to open a new comment window, then type a message and tap “Send.” The message is posted in the comment thread in which the original comment appeared, and the other user's name is automatically added to the comment and appended to the “@” symbol.
Instagram Push Notifications
When you mention a user's name and append it to the “@” symbol, that user receives a push notification that you have commented on her profile. Therefore, any time you want to respond to another user, type the “@” symbol and her username at the beginning of the comment. For example, if her username is “Maria1990,” type “@Maria1990” (without quotes) at the beginning of the comment. You only need to mention her username if the comment is posted to a profile other than hers. She automatically receives a notification when a user comments on her profile.