fou vs fol

[martinkunev]

I had to translate "A crazy woman" and Duolingo said that my translation "Une femme foue" is wrong and it should be "Une femme folle".

What is the difference between these two words and how to decide which one to use in a given context?

[Sitesurf]

You use "fol" only when the (masculine, singular) noun is after the adjective and starts with a vowel (or a non aspired "h"):

Un fol amour

Pls note that the same applies to "beau" -> "bel": un bel homme

[martinkunev]

Thank you, now everything is clear.

I thought that fou and fol were two distinct words for crazy with corresponding feminine forms. The comparison with beau/belle realy helped.

I wonder how I haven't encountered this before...