Thank you guys for your answers

I tried to give him grapes, which he always liked before i took him here, and all he does is flinging them away

I left one between the cage bars and when i turned away he took a bite, but as soon as i moved he threw it too. I guess it will take some time with him, the poor little guy.
My friend has a gardening store and as part of the decoration he has Koi carps and a big cage with lots of birds in, mostly parakeets and australian parakeets, and Sisu came two weeks ago, from the house of a customer.
All he was doing was sitting on the floor of the cage looking down, and hiding inside a plant pot whenever any of the other birds flew over him. That's when my friend asked me if i could take care of him, and since Sisu has always been so chatty and nice every time i sat down in the cage with him, i thought it would be a good idea... But i don't know

he hasn't so much as chirped since he came to my home.
I guess the ride over scared him. But then again he was already stressed when i picked him up this morning. That's when he bit me.
I'll try and respect his space for a few days and see how it goes.... thank you again for the tips
