You know those times when someone hits reply all instead of reply? I find that happens on Twitter all the time. Sometimes I just want to send a GIF or short reply to the person who posted the tweet, not the other 15 people tagged in it. This is possible...here is how:
When you click the reply icon, you see this screen:
Instead of just typing your reply, you can click the names to get a list of all those tagged in the tweet. Then, you can check the box beside "Others in this conversation" to remove all others from the list of who will receive the reply. You can also uncheck names individually to only include some of the others.