dì di / zhǐ / yòng / jǐ tiān / jiù / xué huì / le / yòng / kǒu qín / chuī zòu / yì shǒu / jiǎn dān / de / mín gē

弟弟只用几天就学会了用口琴吹奏一首简单的民歌。

My younger brother learned to play a simple folk song on the harmonica in just a few days.