凭 / 依据 / 依照: on the strength of, based on, in accordance with
【五12-14】介词 / prepositions
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
凭, 依据 and 依照 are three prepositions of basis: they say what a statement or a decision rests on. Choose by what follows: 凭 + something a person has or shows (凭经验, 凭他的水平, 凭票), 依据 + facts or data (依据调查结果), 依照 + a rule, a method or a wish (依照规定, 依照他的意思).
依据 and 依照 are the formal versions of 根据 and 按照: reports, meetings, official texts. 凭 is more flexible and works in speech too; 凭什么 is the challenge "on what grounds?!", "why should…?", which protests rather than asks for a method.
The phrase goes before the verb, with no 的: 依照规定办事, 凭经验判断.
Examples
凭他的经验，这个问题很快就能解决。
Píng tā de jīngyàn, zhège wèntí hěn kuài jiù néng jiějué.With his experience, this problem will be solved in no time.
她凭自己的努力考上了理想的大学。
Tā píng zìjǐ de nǔlì kǎoshàng le lǐxiǎng de dàxué.She got into the university of her dreams through her own hard work.
凭什么他可以迟到，我就不可以？
Píng shénme tā kěyǐ chídào, wǒ jiù bù kěyǐ?Why should he be allowed to be late and not me?
公司依据市场调查的数据，调整了产品的价格。
Gōngsī yījù shìchǎng diàochá de shùjù, tiáozhěng le chǎnpǐn de jiàgé.The company adjusted its product prices based on the market survey data.
请大家依照公司的规定办理手续。
Qǐng dàjiā yīzhào gōngsī de guīdìng bànlǐ shǒuxù.Please complete the formalities in accordance with company regulations.
我们依照他的愿望，把生日晚会安排在家里。
Wǒmen yīzhào tā de yuànwàng, bǎ shēngrì wǎnhuì ānpái zài jiālǐ.In line with his wishes, we arranged the birthday party at home.
Common mistakes
✗ 凭他最近很忙，所以没来 → ✓ 因为他最近很忙，所以没来 (凭 does not give a cause, it gives what you rely on).
✗ 依据他的能力，他当上了经理 → ✓ 凭他的能力，他当上了经理 (a person's quality takes 凭, 依据 expects facts or data).
✗ 依据规定的办事 → ✓ 依照规定办事 (the preposition phrase goes before the verb, no 的).