跑 = 足 (zú, foot) + 包 (bāo, to wrap; phonetic) — a straightforward pictophonetic. The semantic component 足 (in the component form 𧾷) appears on the left and anchors verbs of foot-motion: 走 zǒu (to walk), 跳 tiào (to jump), 跨 kuà (to stride), 踢 tī (to kick), 路 lù (road), 距 jù (distance). The phonetic 包 supplies the sound — Middle Chinese *bauX, modern pǎo — and contributes nothing semantic. The whole image is simple and clean: a foot doing the action that 包 sounds like, which the language settled into the meaning "to run."

Historically 跑 is a relatively late character. Classical Chinese used 走 for both "to walk" (modern sense) and "to run" (classical sense), reserving the more vivid 奔 bēn for galloping or rushing. 跑 appears more prominently in colloquial writing from the Tang dynasty onward and becomes the standard everyday verb for "to run" in modern Mandarin. This is why 走 is a false friend for English-speaking learners: in classical poetry 走 often means "run" (as in 走马观花 "to view flowers from a galloping horse"), and the modern split — 走 walk, 跑 run — is a development of the last millennium.

The semantic field of 跑 in modern Chinese is broader than English "to run" alone:

1. To run (physical motion). The body in fast motion. 跑步 pǎobù "to jog"; 奔跑 bēnpǎo "to dash, to run hard"; 赛跑 sàipǎo "to race."
2. To flee. Running away from danger, capture, or obligation. 逃跑 táopǎo "to flee"; 跑了 pǎo le "got away" (a thief, a debtor, a fish on the line).
3. To run (errands, around). Going from place to place to do things. 跑腿 pǎotuǐ "to run errands"; 跑业务 pǎo yèwù "to drum up business."
4. To run (of vehicles, machines). 这辆车跑得很快 "this car runs fast"; 机器跑起来了 "the machine is up and running."
5. To leak, escape, evaporate. A specifically Chinese extension: gas, steam, water, even ideas can 跑. 气跑了 "the air has escaped"; 味儿都跑了 "the flavor has all gone."

The figurative life of 跑 in modern Chinese stretches well beyond physical running. Three extended senses are worth knowing because they appear constantly in everyday speech and would not be obvious from English "to run" alone.

To go around doing things. 跑 can mean moving from place to place purposefully — running errands, making the rounds, hustling. 跑腿 pǎotuǐ "to run legs" = to do errands; 跑业务 pǎo yèwù = to drum up business; 跑了一整天 "I was on my feet running around the whole day." This sense is closer to "to hustle" or "to run around" than to the athletic sense.

To run (of vehicles and machines). Cars, trains, machines, websites, software all 跑. 这辆车跑得很快 "this car runs fast"; 服务器跑不动了 "the server can no longer run." This is the same metaphor as English "the engine is running" — but in Chinese it has been formalized into 跑车 (sports car) and 跑量 (a vehicle's mileage).

To leak, escape, evaporate. The most distinctively Chinese extension: 跑 is the standard verb for things that get out and away — gas escaping a tire, heat escaping a room, flavor leaving a dish, ink running on paper. 气跑了 "the air has escaped"; 味儿都跑了 "all the flavor has gone"; 颜色跑了 "the color has run." English uses several different verbs for these (escape, leak, evaporate, run); Chinese uses 跑 for all of them.

The 足 / 走 component anchors a small family of foot-motion verbs that learners often confuse. The three most common are:

走 zǒu — to walk (modern); to leave; in classical Chinese, to run. The base verb of foot-motion. Slow speed, ordinary pace.

跑 pǎo — to run. Faster pace than 走. Both feet leaving the ground in alternation. Modern Chinese uses 跑 for the running sense that classical Chinese assigned to 走.

跨 kuà — to stride; to step over; to span. Not about speed but about reach: a single wide step, legs spread, a foot reaching over a boundary. 跨 implies a deliberate stretching of the stride; 跑 implies repeated rapid steps.

The everyday distinction is clean: 走 is walking pace, 跑 is running pace, 跨 is the wide single stride. In compound formation each builds its own family — 走路 走开 / 跑步 跑车 / 跨过 跨界 — and the families do not overlap much. Once you know which physical motion each names, the productive compounds organize themselves around the base.