Wǒ shì xué wénxué de, shù yè yǒu zhuān gōng, gōngchéng wèntí bāng bu shàng máng.
I studied literature — each to their own specialty — I can't help with engineering problems.
Tips
history
From Han Yu's (韩愈) Tang essay 《师说》 (On the Teacher): 闻道有先后，术业有专攻，如是而已 — 'Some hear the Way earlier, some later; every craft has its specialists — that's all there is to it.' Han Yu's argument for humility about learning from anyone qualified, regardless of age or status.
usage
A polite way to defer to an expert or decline a task outside one's field. Often used as a humble refusal. Pair with 闻道有先后 for the full allusion in formal writing.
