Root ك ل ف(k l f) has 4 unique word forms and appears 8 times in the Quran.

English gloss Burdening, Trouble, Discomfort, Ceremony, Cost, Formality, Expenses, Freckled, Spotted

Word Translation Occurrences
نُكَلِّفُ We burden, We burden 6
تُكَلَّفُ are you responsible, is burdened, are you responsible, is burdened 4
يُكَلِّفُ burden, burden 4
ٱلۡمُتَكَلِّفِينَ the ones who pretend, the ones who pretend 2