The "T" at the end is only SORT OF silent. The rule is E without accent (pronounced UH) +T (pronounced tay) = è (that's like the English E in the word "merry") So yes, you heard it, but not as a T. If the "T" was totally silent, "navet" (pronounce it "NA VÈH" would be pronounced "NA VUH" or "NAV-" The same is true with E + S = è (that's why "les" is said [lè] not [less] or [luh].)

Yes, the letter 't' at the end of a word such as 'navet' is silent. The doubling of the consonant and the addition of the 'e' shows that you have to pronounce the 't'. Think of French words which we use in English, such as 'ballet' (the end of the word is 'open' ) , as opposed to 'barrette' (where the 'tte' is pronounced). A single 's' in the middle of a word is pronounced 'z', while the double 'ss' is pronounced 'ss'. So 'baiser' has a 'z' sound in the middle, while 'baisser' has an 'ss' sound.