How to say:when I throw something from height space to the lower space?Q:"throw down"?? How to say:when I throw something from height space to the lower space? Q:"throw down"??

My holiday I'm living in Manchester now, for 3 month to learn English But when I talked with classmates who come from different country. Sometimes they understand, sometimes not. I think I made some mistake of grammar, but I don't know what's wrong with it!! So I tried to wright something, and I wish some one can help me !! thanks

Introducing myself um~ i want to learning english, because i'll have a travel abroad next year with my friend, we didn't with any group, and i find this website,I hope can lean more here!! thanks (i know my grammar/word is fault , please tell me^^)