What's the difference between I opt for the party and I'm up for the party? And, to make it more complex, I'm down for the party.
But I'm especially interested in the first two.
What's the difference between I opt for the party and I'm up for the party? And, to make it more complex, I'm down for the party.
But I'm especially interested in the first two.
"I'm opt for the party" is ungrammatical.
"up for" and "down for" with respect to parties and activities in general mean the same thing: I want to go do it.
The phrase "To be up for something" means
to feel that you are strong or healthy enough to do something
The phrase "To be down for something" is more of a slang term and I always picture it as like when you've put your name down on the list indicating you want to participate then you are down for it.
Note that being "down with" something is a little different and means more like you are in agreement with the sentiment or idea being expressed.
Opting for something is choosing for something. In the context of a party, it sounds unnatural: "I choose for the party".
To be up for something means you are interested for the party, as in "You are already standing up to get on your way to the party".
"Down for" is, I think, bad. I think it should be "down with". Maybe referring to "downtown" (just a guess) ?