外行

他对画画只是个外行。

tā duì huàhuà zhǐ shì gè wàiháng.

He's just an amateur when it comes to painting.

她对烹饪是个门外汉。

tā duì pēngrónɡ shì yīgè ménwài hàn.

She's a novice when it comes to cooking.