Tā bù dǒng zhuāngxiū hái zìjǐ xiāgǎo, jiéguǒ bǎ qiáng nònghuài le.
He knows nothing about renovation but had a go himself, and ended up damaging the wall.
Tips
usage
瞎 "blindly" before a verb means doing it without sense: 瞎说 (to talk nonsense), 瞎猜 (to guess wildly), 瞎忙 (to be busy for nothing). 瞎搞 is casual and critical.
