Questions & Answers about Vi duschar hos grannen ikväll.
Because duschar is the present tense form of the verb duscha (to shower).
- att duscha = to shower
- jag duschar = I shower / I am showering
- vi duschar = we shower / we are showering
In a normal main clause, Swedish needs a finite verb that agrees with the tense, so vi duschar is correct.
It can mean either in principle, but in this sentence it is understood as a future event because of ikväll (tonight / this evening).
Swedish very often uses the present tense for the future when the time is clear:
- Vi duschar hos grannen ikväll. = We’re showering / will shower at the neighbor’s tonight.
- Jag åker imorgon. = I’m leaving tomorrow.
So this is completely normal Swedish.