Adding a phrase to a group
To add a phrase to a phrase group, simply click inside a phrase group:


Using phrase groups
Consider the following phrase group:
you, are and awesome appear anywhere in the message content. So you are awesome could match, but so could awesome are you or even you are not awesome. This also ignores spaces, so you're aren't awesomest would also be matched by Fossabot.
However, you could combine these phrases into a single phrase:

you are awesome!!, but not you are not awesome - as the entire phrase block is not able to be matched anywhere in you are not awesome.
Multiple phrase groups
Assuming a use case where you would like to matchyou are awesome or you are cool, it may be your first instinct to do something like this:

you are cool AND you are awesome. You will want to create multiple phrase groups to create an OR condition, where instead you ask Fossabot to match if either phrase exists.
Click the Add Phrase Group button, it will add another input, and move you are cool into the below phrase group like so:

you are cool OR you are awesome is contained within the message content!