HSK 5
Lǎo Zhāng shì ge yúmù gēda, rènzhǔn de shì shéi quàn yě méiyòng.
Old Zhang is as stubborn as a block of wood: once he has made up his mind, nobody can talk him out of it.
HSK 7-9
Nǐ zhēnshì ge yúmù gēda, zěnme jiǎng dōu bù míngbai!
You really are a blockhead: no matter how I explain it, you don't get it!