0 (used as the object of a verb or preposition, but in everyday speech sometimes replaced by who) what person(s)(?) -- komu, koho, kým
1 (used to refer to a person or people mentioned previously, to distinguish him or them from others; able to be omitted or replaced by that except when following a preposition) (the) one(s) that -- který
2 used, after a comma, to introduce a further comment on a person or people -- který
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.
Můžeme to dokončit krok za krokem, ať je cesta jakkoli dlouhá, a nelze ji dokončit, ať je cesta jakkoli krátká, pokud si ani neoznačíte svou stopu.