"an interesting apartment building"
Translation:un immeuble intéressant
they are two different sounds. I think you need to hear them over and over to really know how they sound. I am not French and don't hear sounds well, and I"ve been told that I am not right, so this is just a suggestion to get you started, not the best sound. I always thought of the first, é as similar to the English long a sound [bay, may, say] but apparently it is not accurate. The second, è I thought of as similar to the short e [egg, bet, seven]. That might help you start but you need to hear a French person say it over and over for your brain and ear to get it. I still need to know where the tongue and lips are myself.