Question

how do I answer a comment in the tree house?

Answer 1

You have to just reply to comments, unfortunately.

Answer 2

Les,

By adding a comment to the chain.  If there is already a string of several comments, you can be specific by starting out with the name of the person to whom you are responding (like I started this answer).

Comments

you can be specific by starting out with the name of the person to whom you are responding (like I started this answer).

answered by Gaile Connolly

.

Or - if you're on a device that allows for copy and paste - you can do as I just did and quote the person. 

(Just don't edit too much of what they said, to make it appear they said something they didn't.)