What can you put in the Altoids tin?

This puzzle was originally created for a group of my friends to solve together. Because it is meant to be "interactive" the description of the setup here is fairly straightforward because I'm describing it via paragraph instead of via visuals.

In front of me I have an Altoids tin and many small pieces of paper. For each line below, I write it on a piece of paper, then crumple it up and put it in the Altoids tin.

I am sick.
I am healthy.
You are poor.
They are wealthy.

Then, I have another friend who offered to help do the same with the following lines:

That is solid.
He was plasma.
Chuck Norris is Texas.
We were Alabama.

Then, we pass the tin and paper around, asking people to try to write individual lines that can also be put in the tin. If their line works, I allowed them to crumple it up and put in in the tin. (If their guess didn't work or did work, I would tell them, so I will confirm phrases in the comments)

A few failed attempts that my friends made:

How are you?
David Tennant

And some that were a bit closer, but also failed:

You are stupid
This is confusing
I like trains
Oregon

And the first successful one:

It is liquid

So, come up with some lines (ideally with varying formats) that can also be put in the tin. Explain why they work.

Once you've done that, there's one last question. In two words, what are we doing?

The final two word answer also involves wordplay.

• Welcome to Puzzling! This seems to run a risk of being too broad - right now, the rule "any phrase can be put in the tin" is completely legitimate. I'd recommend adding a lot more examples and counterexamples - for instance, What is a Cyclone Phrase™? is a similar type of puzzle, and it has 23 of each.
– Deusovi
Sep 17, 2017 at 23:44
• Thank you. I think the answer of this puzzle is a little bit more simple than what is normally put here, as my friends and I are not hardcore puzzle solvers but thought that it was fun. The answer pattern is definitely not as complex as Cyclone Phrase. I'll add in a few more examples of what my friends said though. Sep 18, 2017 at 0:02
• I really think the extra examples shouldn't be spoilered, so we have information about the negative case. Sep 18, 2017 at 0:16
• Ok, just changed it and added that I will confirm phrases in the comments. Sep 18, 2017 at 0:23

I am sick.
I am healthy.

Are states of health.

You are poor.
They are wealthy.

Are states of wealth.

That is solid.
He was plasma.
It is liquid.

Are states of matter.

Chuck Norris is Texas.
We were Alabama.

Are states of America.

Some examples of other phrases that can be put in the tin:

• She was surprised. (Shock)
• I exist. (Being)
• The dog is angry. (Mind)

All of these are

statements.

(And the failed attempts are not.)

In two words, what are we doing?

Making statements.

Which is wordplay on

States in a mint container (state-mint).

We do this by

Making statements about states and crumpling them into the mint tin to make state-mint statements!

• Everything is right except what we are doing. There's a little extra step in there that makes the connection with the sentence structure and the title. I just added another negative example to help. Sep 18, 2017 at 0:38
• Ahhh, missed the wordplay tag. I'm thinking something along the lines of "assigning" or "allocating", but haven't got the wordplay right yet. EDIT: Never mind, I get it. lol Sep 18, 2017 at 0:52
• Awesome, only thing I would want to add is that every sentence is a statement, thus the "crumple and put into tin" being the "making" part (in addition to the other wordplay). Sep 18, 2017 at 0:57
• Edited to add the part about all sentences fitting that pattern. Also a little addendum at the end to summarise. Sep 18, 2017 at 1:06