The French letter “e” can be pronounced in several ways, including closed e (/e/), open e (/ɛ/), schwa (/ə/), or be silent, and its pronunciation can change depending on diacritical marks. The accents ë, è, é, and ê indicate specific pronunciations: ë signals an open e in vowel groups, è denotes an open e to prevent it being silent or reduced, é indicates a closed e sound, and ê shows an open e often linked historically to a lost letter, typically “s”.
https://jakubmarian.com/french-e-e-e-e-e-whats-the-difference/

