ک ل فk-l-f
(س) كَلِفَ يَكْلَفُ كَلَفًاkalifa yaklafu kalafan: to be so fond of a thing that one takes on hardship for it (this verb is not used in the Quran).
Form II (tafʿīl) كَلَّفَ يُكَلِّفُ تَكْلِيْفًاkallafa yukallifu taklīfan: to bind someone to a burdensome task, to lay a responsibility upon. ﴿لَا يُكَلِّفُ اللّٰهُ نَفْسًا اِلَّا وُسْعَهَا﴾ (Al-Baqarah 2:286)
Form V (tafaʿʿul) تَكَلَّفَ يَتَكَلَّفُ تَكَلُّفًاtakallafa yatakallafu takallufan: to force oneself into hardship; to be affected, to pretend.
مُتَكَلِّفٌmutakallif pl. مُتَكَلِّفِيْنَmutakallifīna (active participle, ism fāʿil): one who affects or pretends. ﴿وَمَآ اَنَا مِنَ الْمُتَكَلِّفِيْنَ﴾ (Ṣād 38:86)