even french people get it wrong sometimes: 

I often hear people say: une tentacule   (should be un) 

une astérisque  (should be un)

I'm sure there are a lot more!

c'est pratique !! Merci beaucoup 

Thanks Caroline! This article came at the right time.  I've been studying French for 6 months and this article just put me over a hump.  Merci!

Very useful! There are also 3 nouns that change gender when they become plural, like "amour". Un bel amour, de belles amours.  The 2 others are "délice" and "orgue".

C'est très utile. Je suis si reconnaissante pour cet article! Merci :)