Let’s take a look at the letter “e” without any diacritical marks (if you would like to know what the diacritical marks (i.e. è, é, ê, and ë) do, you can read my previous article).
The letter “e” can form part of some letter groups, such as “oeu” or “eux”, for example: “sœur” (sister) is pronounced /sœʁ/, “ceux” (those) is pronounced /sø/. I don’t consider trying to memorize a list of such letter groups useful; it is much more effective to assimilate them naturally through listening.
Also note: The difference between /œ/ and /ø/ is subtle; when you listen to French, try to remember that there are two different “aauugh” sounds, and try to notice the difference.
E that doesn’t belong to a letter group
Once you know that the “e” you see does not form part of a larger letter group, you have to look at its position in the word. When
- it is the last letter of a word consisting of multiple syllables, or
- such a word ends in the group “es”, or
- it is a verb and ends in “ent”
The fact that the final “e” or a group with it is silent does not mean that it has no function at all. As you probably know, in French, final consonants are often silent. For example, il sort (he leaves) is pronounced /il sɔʀ/. However, when a silent “e” or a silent group of letters with “e” follows the final consonant, it becomes audible, so ils sortent (they leave) is pronounced /il sɔʀt/.
Notice also that although the final “s” is almost always silent, it does not make the previous consonant audible, e.g. petit (small) and petits (small plural) are both pronounced /pəti/, but petite (small feminine) and petites (small feminine plural) are both pronounced /pətit/. The -s for plural actually in rare cases ‘erases’ the previous consonant; for example, oeuf (egg) is pronounced /œf/, but oeufs (eggs) is just /ø/.
Another important function of a silent “e” is to change the pronunciation of “g” from /g/ to /ʒ/. The verb manger is always pronounced with the /ʒ/ sound (as in the English word massage), but mangons (a non-existing word), which one could expect as the first person plural form of manger, would be pronounced with /g/ (“g” before “a”, “o”, and “u” is pronounced as in “go”). Therefore, it is written as mangeons, to change the pronunciation to /ʒ/.
If none of the above is the case, the pronunciation is decided according to whether “e” is in an open or a closed syllable. You can read more about the topic in my next article.