It's a fantasy role-playing game.

DM: You are Keyleth, a half-elf druid . You are the member of the famous group of adventurers. Previously,  The group of adventurers, Vox Machina, had found themselves in the Feywild, intent on discovering another one of the Vestiges of the Divergence, one of the many artifacts that they hope will aid them in their struggle against Thordak the Cinder King and the rest of the Chroma Conclave. They've defeated two of the members, three still remain, Thordak being the seeming powerhouse head of that troupe.
DM: He does. However, in the purposes of this type of circumstance, it's usually meant for smaller plants that have no sentience that you can normally interact with, like roses and petunias.
Player: I've done this before with talking to the treant.
DM: You can probably communicate with it, yes. I'm saying, issuing commands on this might be a little more difficult for the rest of the spells.
Player: What if I cast at a higher level? Would that help?
DM: This is not a spell that can be cast at a higher level, unfortunately. So what do you want to do? You're casting Speak With Plants.
Player: Well, I cast it, so I'm going to say Hey! You spit that out of your mouth right now, mister! You don't know where that's been! And trust me, I do.
DM: Make an intimidation check. (cheering)
