Uyini umehluko phakathi kwezimpahla zesikhathi esizayo nezinketho?
Inketho inika umthengi ilungelo, kodwa hhayi isibopho, sokuthenga (noma ukuthengisa) impahla ngentengo ethile nganoma yisiphi isikhathi phakathi nesikhathi sokusebenza kwenkontileka. Inkontileka yesikhathi esizayo iphoqa umthengi ukuba athenge impahla ethile, futhi umthengisi athengise futhi alethe leyo mpahla, ngosuku oluthile lwesikhathi esizayo.