"Please put on a tie at this party."
I haven't been commenting on the English because other people have been doing that just fine. But does this really mean that someone goes to the party and then puts on the tie, like the English translation says, or does it mean that a person should wear the tie because they are going to a party? "Please put on a tie "for" this party." I don't normally see people putting on ties "at" parties. They're usually already fully dressed when they show up.