First lets have a look at something that we know: the tubby e. As mentioned before the phonetic script shows a head-down e. We know the sound from words like further, girl, world. You know the sound and it should not be any problem to pronounce the following words.
This sound is represented by only one grapheme (e), one letter which represents this sound, as opposed to English, which has at least three different graphemes for this sound. This does not mean that every e is pronounced this way. The letter e represents other sounds as well, as we shall see.