(ن) خَلَفَ يَخْلُفُ خَلْفًاkhalafa yakhlufu khalfan: to be behind; (1) to succeed someone, to come after someone; (2) to fall short of being like someone, to be changed or different, to be an unworthy successor. ﴿فَخَلَفَ مِنْۢ بَعْدِهِمْ خَلْفٌ اَضَاعُوا الصَّلٰوةَ﴾ (Maryam 19:59)
خَلْفَkhalfa (noun of time or place, ẓarf): behind. ﴿يَعْلَمُ مَا بَيْنَ اَيْدِيْهِمْ وَمَا خَلْفَهُمْ﴾ (Al-Baqarah 2:255)
خَلِيْفَةٌkhalīfah pl. خُلَفَاءُkhulafāʾu and خَلَآئِفُkhalāʾifu: successor. ﴿اِنِّيْ جَاعِلٌ فِي الْاَرْضِ خَلِيْفَةً﴾ (Al-Baqarah 2:30); ﴿هُوَ الَّذِيْ جَعَلَكُمْ خَلٰٓئِفَ فِي الْاَرْضِ﴾ (Fāṭir 35:39)
Form IV (ifʿāl) اَخْلَفَ يُخْلِفُ اِخْلَافًاakhlafa yukhlifu ikhlāfan: (1) to break a promise. ﴿اِنَّ اللّٰهَ لَا يُخْلِفُ الْمِيْعَادَ﴾ (Āl ʿImrān 3:9); (2) to give something in return for a thing. ﴿وَمَآ اَنْفَقْتُمْ مِّنْ شَيْءٍ فَهُوَ يُخْلِفُهُۥ﴾ (Sabaʾ 34:39)
Form II (tafʿīl) خَلَّفَ يُخَلِّفُ تَخْلِيْفًاkhallafa yukhallifu takhlīfan: to leave behind, to put behind; مُخَلَّفٌmukhallaf (passive participle, ism mafʿūl): left behind. ﴿سَيَقُوْلُ لَكَ الْمُخَلَّفُوْنَ مِنَ الْاَعْرَابِ﴾ (Al-Fatḥ 48:11)
Form III (mufāʿalah) خَالَفَ يُخَالِفُ مُخَالَفَةً وَخِلَافًاkhālafa yukhālifu mukhālafatan wa-khilāfan: to adopt a course contrary to someone. ﴿فَلْيَحْذَرِ الَّذِيْنَ يُخَالِفُوْنَ عَنْ اَمْرِهِۦٓ﴾ (An-Nūr 24:63)
Form V (tafaʿʿul) تَخَلَّفَ يَتَخَلَّفُ تَخَلُّفًاtakhallafa yatakhallafu takhallufan: to deliberately stay behind. ﴿اَنْ يَّتَخَلَّفُوْا عَنْ رَّسُوْلِ اللّٰهِ﴾ (At-Tawbah 9:120)
Form VIII (iftiʿāl) اِخْتَلَفَ يَخْتَلِفُ اِخْتِلَافًاikhtalafa yakhtalifu ikhtilāfan: to be at variance, to differ; to come and go, to alternate. ﴿وَاخْتِلَافِ الَّيْلِ وَالنَّهَارِ﴾ (Al-Baqarah 2:164)
Form X (istifʿāl) اِسْتَخْلَفَ يَسْتَخْلِفُ اِسْتِخْلَافًاistakhlafa yastakhlifu istikhlāfan: to make someone a successor. ﴿لَيَسْتَخْلِفَنَّهُمْ فِي الْاَرْضِ﴾ (An-Nūr 24:55)