Usages of ~ina
친구들이 몇 명이나 왔어요?chingudeuri myeot myeongina wasseoyo?
How many friends came?
어제 두 시간이나 공부했어요.eoje du siganina gongbuhaesseoyo.
I studied for as long as two hours yesterday.
Elon.io is an online learning platform
We have an entire course teaching Korean grammar and vocabulary.