In Greek:
1/ «Αγάπη» (a'ɣapi f.); Classical feminine noun «ἀγάπη» (ă'gāpē)-->init. affection, erotic love later love, brotherly love, with unknown etymology. Verb «ἀγαπάω/ἀγαπῶ» (ăgă'pāō [uncontracted]/ăgă'pō [contracted]), in Modern Greek «αγαπάω/αγαπώ» (aɣa'pao [uncontracted]/aɣa'po [contracted]-->to love.
2/ «Στοργή» (stor'ʝi f.); Classical feminine noun «στοργὴ» (stŏr'gē)-->love, affection (especially of parents to children), PIE base *sterg-, to guard, care (cognate to Irish, serc, Welsh, serch). Verb «στέργω» ('stĕrgō)-->to be fond of, love (the mutual love of parents and children or of king and his subjects). Although in Modern Greek, «στοργή» has retained its ancient meaning, with «στέργω» ('sterɣo) or folkish «στρέγω» ('streɣo) we mean to condescend.
3/ «Έρωτας» ('erotas m.); Classical masculine noun «ἔρως» ('ĕrōs)-->init. sexual passion, desire later passionate love of unknown etymology. Verb «ἔραμαι» ('ĕrāmæ)-->to love, desire (it has not survived in the modern language). Modern Greek «ερωτεύομαι» (ero'tevome)-->to fall in love.
4/ «Φιλία» (fi'lia f.); Classical feminine noun «φιλία» (pʰĭ'līă)-->affectionate regard, friendship of unknown origin. Verb «φιλέω/φιλῶ» (pʰĭ'lĕō [uncontracted]/pʰĭ'lō [contracted])-->to treat affectionately or kindly. In the modern language, «φιλώ» (fi'lo) means to kiss. «Φιλία» (fi'lia) in Modern Greek is solely the friendship. The prefix «φιλο-» (philo-) is productive of a great many compounds (i.e. philology, philosophy etc)