DAVID: Hey, Grammarians. Hey, Paige. 

PAIGE: Hi, David. 

DAVID: Hey. So, Paige, I went to the grocery store yesterday, and I got this apple. And I put it in the fridge. And this morning, when I opened the fridge, the apple was all gross and sticky and mushy. And I really want to write a letter to the grocery store and say, hey, you sold me a gross apple. But I'm stuck. I feel like I ought to put a comma in here. So here's the sentence. I've got so far. You sold me a mushy, sticky apple. 

PAIGE: Gross. 

DAVID: Gross, unacceptable. 

PAIGE: Totally. 

DAVID: So I would like my $1.38 back. But in another draft of the letter, I wrote, you sold me a mushy green apple. 

PAIGE: OK, so mushy sticky or mushy green. 

DAVID: Yeah. And I feel like-- and I don't know how to put this into words yet, but we're going to put it into words because that's our job-- whether or not there should be a comma in between mushy and green or mushy and sticky. Because these feel different to me. 

PAIGE: Right, right. Yeah, so there's actually a couple tests that you can do on these sentences to see if you need a comma between the adjectives or not. 

DAVID: So, Paige, what distinguishes a pair like mushy and sticky from mushy and green? 

PAIGE: There's this sort of hierarchy or order that you put adjectives in when you have multiple of them in a sentence. And it is called DOSA SCOMP. 

DAVID: DOSA SCOMP-- altogether now. D, Determiner. O, Opinion. S, Size. A, Age. S again, Shape. C, Color. O, Origin. M, Material. And P, Purpose. OK. So mushy and sticky are both opinion adjectives. So these are kind of in the same class, whereas mushy and green, that's an opinion and a color. 

PAIGE: Yeah, they're in two different classes. 

DAVID: Right. So DOSA SCOMP helps determine adjective order. So if you were stacking these adjectives, you would use them in this DOSA SCOMP order. 

PAIGE: Right. So in the second sentence, mushy is an opinion, like you said, and green is a color. And in DOSA SCOMP, opinion comes before color. So that's the order that you write them in. So in the first sentence, when you have mushy and sticky, which are both opinion adjectives, these are called coordinate adjectives. They're in the same category of DOSA SCOMP. And if you wanted to, you could reverse the order. You could say sticky, mushy apple. 

DAVID: Well, let's try that. Looks good to me-- sticky mushy, mushy sticky. 

PAIGE: Same thing. 

DAVID: OK. So if we're trying to determine whether or not we have coordinate adjectives, the first thing we would do is consult DOSA SCOMP. So that's step one. And what is a dosa, Paige? 

PAIGE: Oh, it's like a pancake, right? 

DAVID: Yeah it's like a South Indian pancake. 

PAIGE: That's pretty cool. 

DAVID: And to scomp is a word we made up that means to eat. 

PAIGE: Sure. Eat some pancakes. 

DAVID: Scomp on them. So that's step one. Step two, try the reversal method. 

PAIGE: Right. And that's like changing it from mushy sticky to sticky mushy. 

DAVID: And step three is, stick an "and" in there. 

PAIGE: If you can reverse the order of the adjectives and you can put "and" in between the two of them, then they're coordinate adjectives. 

DAVID: And if they're coordinate adjectives, you need to separate them with comma. 

PAIGE: Exactly. And that's why in the case of the second sentence with mushy green apple, you don't put a comma between them. They're in different categories in DOSA SCOMP, and so they must stay in that order and there's no need for a comma. 

DAVID: Thanks, Paige. I'm going to get back to drafting my angry letter. You can learn anything. David out. 

PAIGE: Paige out.