Questions & Answers about Minä voitan potin, jos valtti on minulla.
Why is the word order valtti on minulla instead of the usual minulla on valtti?
In Finnish, word order shows what is known versus what is new information. Minulla on valtti introduces new information, translating to "I have a trump." By putting valtti first (valtti on minulla), it becomes the known topic: "The trump is with me" or "I am the one who has the trump."
Why does potti take the -n ending to become potin?
Potin is the object of the sentence. Because the action of winning the pot is a complete, finished action—and you win the entire pot—it takes the genitive-accusative -n ending (a total object). If the sentence was negative, meaning the action didn't happen ("I don't win the pot"), it would require the partitive case (pottia).
Is the pronoun minä strictly necessary before voitan?
Grammatically, no. The -n ending on voitan already tells us "I win", so you could perfectly well say Voitan potin. Including the pronoun minä here adds emphasis, making it sound more like "I win the pot (and you don't)."
Is the word valtti only used for card games?