puzzle game where the combination of words do something

Hi! I'm new at c#, and im trying to make a game where the combination of a verb and a noun, do something. On left click, the selected word (a gameObject) goes on a slot. there are two slots one for verbs one for nouns. So, you choose "open" from verbs and the word goes to the verb slot, and "door" from nouns and the word goes in the noun slot. the phrase "open door" created, and the character opens the door. I'm looking for a way to manage the combinations.

Thanks in advance!